36-Week WAEC Revision Programme — Technical Drawing
September to the May WAEC sitting. SS3 is not a year of new material so much as a year of pressure on material already met, so this is not a course to work through from the beginning — it is a testing programme. Each week you answer cold, work the ones you got wrong, and have the AI explain why you got them wrong. Anything you turn out never to have been taught, you learn there and then, and meet again three weeks later.
A week is one block of the syllabus and the prompts that cover it. You are not meant to do all of them: answer the questions first, and let what you get wrong decide which of the rest you need. Fifteen or twenty minutes a subject is a real week's work — nine subjects do not fit any other way.
Every week, in this order
Start with the questions, not the explanation. The first two steps are in every week; a purpose-written mistake or pitfalls prompt appears in about half of them, and where it does not, your own wrong answers are the material for step three.
- 1. Retrieve — Answer cold, with nothing in front of you. Wrong answers are the point — they show you where the week's work is.
- 2. Drill — Work the ones you missed properly, showing every step, so you and the AI can both see where it went wrong.
- 3. Explain my error — Ask why your answer was wrong, not just what the right one is. Where the week offers a Spot My Mistake or WAEC Pitfalls prompt, use it.
- 4. Teach me — Only if the error turns out to be something you were never taught. Then come back and retrieve it again.
Drawing Fundamentals
↑ Jump to week- Week 1
- Quiz: The T-square and set squares and the angles they give
- WAEC prep: The grades of pencil used in technical drawing
- Practice set: Setting up a drawing sheet with border and title block
- Spot my mistake: Assuming a single set square will give every angle a drawing requires
- Let me explain: Compasses, dividers and the protractor
- Teach me: The A2 ISO drawing board and how the sheet is fixed to it
- Week 2
- Quiz: Continuous thick, continuous thin and chain lines
- WAEC prep: Dimensioning rules: extension lines, arrowheads and placement
- Practice set: Dimensioning a given outline correctly
- Spot my mistake: Using a chain line where a hidden edge should be shown
- Let me explain: Single stroke lettering and its proportions
- Teach me: The types of line in BS 1192 and what each means
- Week 3
- Quiz: Bisecting a line and erecting a perpendicular
- WAEC prep: Applications of line division in layout work
- Practice set: Dividing a stated line into seven equal parts
- Spot my mistake: Dividing a line into equal parts by measuring with a rule instead of by construction
- Let me explain: Dividing a line in a given ratio
- Teach me: Dividing a straight line into equal parts by construction
- Week 4
- Quiz: Constructing a plain scale
- WAEC prep: The scale of chords and its use in setting out angles
- Practice set: Constructing a diagonal scale to a stated RF
- Spot my mistake: Reading the representative fraction as the ratio of the drawing to the sheet rather than to the object
- Let me explain: Constructing a diagonal scale and reading it
- Teach me: What a scale is and how the representative fraction works
Revisit from three weeks ago
Plane Geometry
↑ Jump to week- Week 5
- Quiz: Bisecting an angle
- WAEC prep: Dividing an angle into a given number of equal parts
- Practice set: Constructing stated angles without a protractor
- Spot my mistake: Assuming any angle can be constructed with compasses by repeated bisection
- Let me explain: Constructing 30, 45 and 75 degree angles
- Teach me: Constructing 60 and 90 degree angles with compasses
Revisit from three weeks ago - Week 6
- Quiz: The properties of the special quadrilaterals
- WAEC prep: Constructing a polygon within a given circle
- Practice set: Constructing an irregular polygon from given data
- Spot my mistake: Assuming a polygon constructed on a given side will also fit a given circle
- Let me explain: Constructing a regular polygon on a given side
- Teach me: Constructing a triangle from given sides and angles
Revisit from three weeks ago - Week 7
- Quiz: Finding the centre of a given arc
- WAEC prep: Constructing circles in contact with one another
- Practice set: A construction combining arcs and circles
- Spot my mistake: Treating a chord and a diameter as interchangeable when finding the centre of an arc
- Let me explain: Constructing a circle through three given points
- Teach me: The parts of a circle and the terms for each
Revisit from three weeks ago
Geometric Constructions
↑ Jump to week- Week 8
- Quiz: Drawing a tangent to a circle from an external point
- Quiz: Circumscribing a circle about a triangle
- WAEC prep: Applying tangency to a spanner or anchor outline
- Practice set: Blending arcs and lines by tangency
- WAEC prep: Inscribing a polygon in a circle
- Spot my mistake: Drawing a tangent that meets the radius at the point of contact at any convenient angle
- Spot my mistake: Confusing the incentre with the circumcentre
- Let me explain: Internal and external common tangents to two circles
- Let me explain: The escribed circle and how it is constructed
- Teach me: The principle of tangency and the right angle at the point of contact
- Teach me: Inscribing a circle in a triangle
Revisit from three weeks ago - Week 9
- Quiz: Enlarging a figure by a given ratio of sides
- WAEC prep: Constructing a figure equal in area to a given one
- Practice set: Reducing a polygon to two thirds of its area
- Spot my mistake: Doubling every side of a figure in order to double its area
- Let me explain: Enlarging or reducing a figure by area
- Teach me: What makes two figures similar
Revisit from three weeks ago - Week 10
- Quiz: Constructing an ellipse by the concentric circle method
- WAEC prep: The cycloid, involute and helix
- Practice set: Plotting the locus of a point on a link mechanism
- Spot my mistake: Treating an ellipse as a shape struck from four centres rather than plotted as a locus
- Let me explain: Constructing a parabola and a hyperbola
- Teach me: What a locus is and how one is plotted
Revisit from three weeks ago
Solid Geometry and Projections
↑ Jump to week- Week 11
- Quiz: The true length of a line by rotation
- WAEC prep: Traces of a line and of a plane
- Practice set: Finding true length and inclination from given views
- Spot my mistake: Assuming the longer of the two given views of a line shows its true length
- Let me explain: The angle of inclination of a line to a plane
- Teach me: Locating a point and a line in space
Revisit from three weeks ago - Week 12
- Quiz: Oblique projection and the receding axis
- Quiz: The arrangement of views in first angle
- WAEC prep: Two-point perspective and the vanishing points
- Practice set: Drawing one object in all three pictorial methods
- WAEC prep: The projection symbols and reading them
- Practice set: Drawing three views of a given solid
- Spot my mistake: Treating an isometric drawing as a perspective view with lines converging on a vanishing point
- Spot my mistake: Placing the plan above the front view in first angle projection
- Let me explain: One-point perspective
- Let me explain: The arrangement of views in third angle
- Teach me: The isometric axes and how a solid is set out on them
- Teach me: The principle of orthographic projection
Revisit from three weeks ago - Week 13
- Quiz: Constructing a first auxiliary view
- WAEC prep: Auxiliary views of prisms and pyramids
- Practice set: Projecting an auxiliary view from given views
- Spot my mistake: Projecting an auxiliary view at right angles to the frontal plane rather than to the inclined face
- Let me explain: The second auxiliary projection
- Teach me: Why an auxiliary view is needed
Revisit from three weeks ago - Week 14
- Quiz: The cutting plane and its indication
- Quiz: Developing the surface of a prism
- WAEC prep: True shape of a section of a cone: ellipse, parabola and hyperbola
- Practice set: Drawing a section and its true shape
- WAEC prep: Developing a cone and a pyramid
- Practice set: Developing a truncated solid
- Spot my mistake: Hatching the whole sectional view rather than only what the cutting plane passes through
- Spot my mistake: Developing the curved surface of a cone as a rectangle of the same height
- Let me explain: True shape of a section of a prism
- Let me explain: Developing the surface of a cylinder
- Teach me: Why a sectional view is drawn and how it is hatched
- Teach me: What a development is and how it is used
Revisit from three weeks ago
Surfaces and Forces
↑ Jump to week- Week 15
- Quiz: Intersection of two cylinders of equal diameter
- Quiz: Conventional representation of repeated features
- WAEC prep: Intersection of a cone with a cylinder
- Practice set: Plotting a curve of interpenetration point by point
- WAEC prep: Conventions for breaks and partial views
- Spot my mistake: Assuming the intersection of two equal cylinders meeting at right angles is always a curve
- Spot my mistake: A drawing that misuses a standard symbol
- Let me explain: Intersection of cylinders of unequal diameter
- Let me explain: Abbreviations used on engineering drawings
- Teach me: Why solids intersect and what the curve of intersection is
- Teach me: The symbols for diameter, radius and square
Revisit from three weeks ago - Week 16
- Quiz: Bow's notation and how forces are lettered
- WAEC prep: The polygon of forces and the resultant
- Practice set: Finding the equilibrant of a given force system
- Spot my mistake: Treating the resultant and the equilibrant of a force system as the same force
- Let me explain: The triangle of forces
- Teach me: Coplanar and concurrent forces
Revisit from three weeks ago - Week 17
- Quiz: Finding internal forces in frame members
- WAEC prep: Shearing force diagrams for a simply supported beam
- Practice set: Drawing a bending moment diagram for a cantilever
- Spot my mistake: Deciding a frame member is a tie because it is horizontal
- Let me explain: Identifying ties and struts
- Teach me: Reactions at the supports of a simple frame
Revisit from three weeks ago - Week 18
- Quiz: Solid and suspended floors
- Quiz: Columns, beams and lintels
- WAEC prep: The parts of a staircase and stair terminology
- Practice set: Drawing a section through a roof
- WAEC prep: Reading a services layout and tracing a circuit through it
- Practice set: Drawing a floor plan to a stated scale
- Spot my mistake: Assuming every floor in a building is a solid floor cast on the ground
- Spot my mistake: Reading a floor plan as a view from above rather than as a horizontal section through the building
- Let me explain: The parts of a door and of a window
- Let me explain: The drawings that make up a set of working drawings
- Teach me: Strip, pad and raft foundations
- Teach me: Wall construction and the courses of brickwork
Revisit from three weeks ago
Mechanical Drawing
↑ Jump to week- Week 19
- Quiz: The conventional representation of a screw thread
- WAEC prep: Full, half and part sections
- Practice set: Dimensioning a machined component fully
- Spot my mistake: Treating a tolerance as the error the workshop is expected to make rather than the permitted range of size
- Let me explain: Nuts, bolts and locking devices
- Teach me: Limits, fits and tolerances
Revisit from three weeks ago - Week 20
- Quiz: Freehand pictorial sketching of components
- Quiz: The half section on a symmetrical part
- WAEC prep: The assembly drawing and the parts list
- Practice set: Producing an assembly from given detail drawings
- WAEC prep: Parts that are never sectioned, and why
- Practice set: Drawing a half section of a given component
- Spot my mistake: Dimensioning every part fully on an assembly drawing
- Spot my mistake: Sectioning a shaft, a bolt or a rib along its length
- Let me explain: The detail drawing and what it must show
- Let me explain: The part or local section
- Teach me: Isometric drawing of a machine part
- Teach me: The full section and when it is used
Revisit from three weeks ago
Mixed WAEC Practice
↑ Jump to week- Week 21
- Quiz: The carpenter's tools used on site
- WAEC prep: Sketching a building tool in orthographic view
- Practice set: A timed freehand sketch of a trowel, a plumb bob and a spirit level
- Spot my mistake: Sketching a tool in orthographic views where a pictorial view is asked for
- Let me explain: Sketching a building tool in pictorial view
- Teach me: The bricklayer's tools and their uses
Revisit from three weeks ago - Week 22
- Quiz: Measuring and marking-out tools
- Quiz: The ground conditions that call for a strip foundation
- WAEC prep: Sketching a mechanical tool orthographically
- Practice set: A timed freehand sketch of a vice, a micrometer and a try square
- WAEC prep: Pile foundations and difficult ground
- Practice set: Drawing a foundation detail in section
- Spot my mistake: Assuming a try square and a bevel do the same job
- Spot my mistake: Assuming a raft foundation is chosen where the ground is strongest
- Let me explain: Sketching a mechanical tool pictorially
- Let me explain: Pad and raft foundations
- Teach me: The fitter's hand tools and their uses
- Teach me: Why a building needs a foundation
Revisit from three weeks ago - Week 23
- Quiz: Hardcore, blinding and damp proof membrane
- WAEC prep: Suspended concrete floors
- Practice set: Drawing a floor detail to scale
- Spot my mistake: Placing the damp proof membrane beneath the hardcore in a solid floor
- Let me explain: Suspended timber floors and their members
- Teach me: The parts of a solid ground floor
Revisit from three weeks ago - Week 24
- Quiz: Types of window and where each is used
- Quiz: The types of staircase by plan shape
- WAEC prep: Types of arch and the terms for their parts
- Practice set: Drawing an arch with its voussoirs
- WAEC prep: The rules governing rise and going
- Practice set: Setting out a straight flight to given dimensions
- Spot my mistake: Treating a casement window and a sash window as the same type
- Spot my mistake: Treating the going and the tread of a stair as the same dimension
- Let me explain: The parts of a panelled door
- Let me explain: The strings, newel and balustrade
- Teach me: The parts of a casement window
- Teach me: Tread, riser, going and pitch
Revisit from three weeks ago - Week 25
- Quiz: Lean-to, gable and hipped roofs
- WAEC prep: Flat roofs and their falls
- Practice set: Drawing a truss to scale
- Spot my mistake: Assuming a flat roof is laid truly level
- Let me explain: The members of a king post truss
- Teach me: The parts of a pitched roof
Revisit from three weeks ago - Week 26
- Quiz: Bonding in brick and block walls
- Quiz: Positioning sockets, switches and light points
- WAEC prep: Lintels over openings and their bearing
- Practice set: Drawing a detail at a wall and beam junction
- WAEC prep: Sanitary fittings and their drainage
- Practice set: Adding services to a given floor plan
- Spot my mistake: Assuming every wall in a building carries load
- Spot my mistake: Reading the line joining two electrical symbols on a plan as the actual route of the cable
- Let me explain: Reinforced concrete columns and beams
- Let me explain: Plumbing symbols and pipe runs
- Teach me: Load bearing and non-load bearing walls
- Teach me: Electrical symbols used on a building plan
Revisit from three weeks ago - Week 27
- Quiz: Representing brick, block and concrete in section
- Quiz: Fillet and butt weld symbols
- WAEC prep: The conventions of BS 1192 for building drawings
- WAEC prep: Common abbreviations on engineering drawings
- Practice set: Annotating a joint with the correct weld symbol
- Spot my mistake: A section hatched with the wrong material convention
- Spot my mistake: Reading a weld symbol below the reference line as though it sat above it
- Let me explain: Representing timber, insulation and hardcore
- Let me explain: Reading weld size and length from a symbol
- Teach me: The hatching conventions for common building materials
- Teach me: The parts of a welding symbol
Revisit from three weeks ago - Week 28
- Quiz: Upper and lower limits of size
- WAEC prep: The hole basis and shaft basis systems
- Practice set: Computing limits from a stated fit
- Spot my mistake: Assuming a transition fit always leaves clearance
- Let me explain: Clearance, interference and transition fits
- Teach me: What a tolerance is and why it is specified
Revisit from three weeks ago - Week 29
- Quiz: Metric, square and acme thread forms
- WAEC prep: The conventional representation of threads in section
- Practice set: Drawing a bolted joint
- Spot my mistake: Drawing the true helix of a screw thread rather than its conventional representation
- Let me explain: Bolts, studs and set screws
- Teach me: The elements of a screw thread
Revisit from three weeks ago - Week 30
- Quiz: Lock nuts and castle nuts
- Quiz: The broken-out section
- WAEC prep: Split pins and wiring as locking methods
- Practice set: Drawing a locked nut assembly
- WAEC prep: The aligned section and when it is proper
- Practice set: Choosing the right section type for a given part
- Spot my mistake: Assuming a plain washer locks a nut against loosening
- Spot my mistake: Showing the steps of an offset cutting plane as lines in the sectional view
- Let me explain: Spring washers and tab washers
- Let me explain: Removed and revolved sections
- Teach me: Why a fastener needs locking
- Teach me: The offset section and its stepped cutting plane
Revisit from three weeks ago - Week 31
- Quiz: Isometric drawing against true isometric projection
- WAEC prep: Non-isometric lines and how they are plotted
- Practice set: Drawing a solid with curved faces in isometric
- Spot my mistake: Treating isometric drawing and true isometric projection as giving a view of the same size
- Let me explain: Drawing an isometric circle by the four-centre method
- Teach me: Constructing an isometric scale
Revisit from three weeks ago - Week 32
- Quiz: Choosing the face to place parallel to the plane
- Quiz: Setting up a one-point perspective
- WAEC prep: The advantages and limits of oblique drawing
- Practice set: Drawing a component in cabinet oblique
- WAEC prep: Perspective of a simple building
- Practice set: Freehand perspective sketching of an interior
- Spot my mistake: Assuming cavalier and cabinet oblique use the same depth along the receding axis
- Spot my mistake: Assuming the horizon line sits at the top of the sheet whatever the viewpoint
- Let me explain: Oblique circles and curves
- Let me explain: Setting up a two-point perspective
- Teach me: Cavalier and cabinet oblique
- Teach me: The horizon line, vanishing point and station point
Revisit from three weeks ago - Week 33
- Quiz: The position of the plan and end views
- Quiz: The position of views in third angle
- WAEC prep: Hidden detail in first angle views
- Practice set: Drawing full first angle views of a given solid
- WAEC prep: Reading a third angle drawing correctly
- Spot my mistake: Leaving hidden detail out of a first angle view because it cannot be seen
- Spot my mistake: Views arranged in the wrong angle of projection
- Let me explain: Projecting a third view from two given views
- Let me explain: Converting a first angle drawing to third angle
- Teach me: How the object sits relative to the planes in first angle
- Teach me: How the planes lie between viewer and object in third angle
Revisit from three weeks ago - Week 34
- Quiz: Finding true length by rotation
- WAEC prep: The angle a line makes with the horizontal plane
- Practice set: Finding true length and both inclinations
- Spot my mistake: Assuming a line inclined in both views can have its true length measured in either
- Let me explain: Finding true length by auxiliary projection
- Teach me: Why a line appears shorter than its true length
Revisit from three weeks ago - Week 35
- Quiz: The edge view of a plane
- Quiz: The frustum of a cone and of a pyramid
- WAEC prep: The angle between two intersecting planes
- Practice set: Finding the intersection of two given planes
- WAEC prep: Transition pieces joining a square to a round
- Practice set: Developing a transition piece
- Spot my mistake: Measuring the angle between two planes in a view where neither appears as an edge
- Spot my mistake: Developing a transition piece as one flat shape without triangulation
- Let me explain: The line of intersection of two planes
- Let me explain: Developing the surface of a frustum
- Teach me: The horizontal and vertical traces of a plane
- Teach me: What truncation does to a solid
Revisit from three weeks ago - Week 36
- Quiz: The centroid of a rectangle and a triangle
- WAEC prep: The centroid of a figure with a cut-out
- Practice set: Locating the centre of gravity of a given lamina
- Spot my mistake: Assuming the centre of gravity of a lamina must lie within its outline
- Let me explain: Finding the centroid of a composite figure
- Teach me: What the centre of gravity of a lamina means
Revisit from three weeks ago