How to prepare for WASSCE Technical Drawing

Topic areas to revise

These are the areas candidates revise for WASSCE Technical Drawing. A heading is not a promise that every unit appears on your paper. Glearn does not host the WAEC file. If the file your school gives you uses a different name, follow the file.

1. 1. Instruments, lines, lettering and dimensioning

   A tee square, with its head against the working edge of the board, draws horizontal lines. Set squares on the tee square draw vertical lines and the angles they are cut to, including 30, 45 and 60 degrees. A compass draws circles and arcs. Dividers transfer a length. A protractor measures an angle. When the question says construct, build the angle with compass and straight edge. A thick continuous line is a visible outline. A thin continuous line is for construction, dimension and projection. A broken line shows a hidden edge. A chain line, a long stroke and a short stroke, marks a centre. Lettering is freehand, between guidelines, at one height. A title block carries the name of the drawing, your name, the scale, and the angle of projection. Extension lines leave a small gap at the object. Place figures so they read from the bottom or from the right. Do not repeat a dimension, and do not let a chain of sizes disagree with the overall size.

2. 2. Plane geometry

   Bisect a line and an angle. Erect a perpendicular. Divide a line into equal parts or into a given ratio. A plain scale reads one unit. A diagonal scale reads a smaller part of that unit. Construct triangles, quadrilaterals and regular polygons. Know the parts of a circle, and how to draw a tangent and a common tangent. Inscribed, circumscribed and escribed figures each touch the circle in a different way. Similar figures keep the same shape at another size. A locus is the path of a point that moves under a rule. An ellipse, a parabola and a hyperbola are loci. A cycloid is the path of a point on a circle rolling along a straight line. An involute is the path of a point on a string as it unwinds. Leave the construction visible and light. A fair curve with the construction erased cannot be marked for method.

3. 3. Solid geometry

   In first angle, the view is placed on the opposite side from the side you looked from. The plan goes below the front view, and the view from the left goes on the right. In third angle, the view is placed on the same side you looked from. The plan goes above the front view, and the view from the left goes on the left. Do not mix the two on one sheet. State which one you used. An auxiliary view is projected at right angles to an edge you want in true length, or to a face you want in true shape. A second auxiliary is projected from the first. A section is the solid imagined to be cut. The true shape is the actual shape of that cut face, not the foreshortened shape in the front view. A development is the surface laid flat. Use true lengths. A cylinder opens into a rectangle whose width equals the circumference of the base. A cone opens into a sector whose arc equals that circumference. Where two solids meet, draw generators, mark where each generator meets the other solid, and join the points in order.

4. 4. Vector geometry for Ghana

   Candidates in Ghana revise vector geometry for the essay paper. A resultant is the single force that can replace a system. An equilibrant is equal and opposite to the resultant and brings the system to rest. Three forces in equilibrium close as a triangle. More than three close as a polygon. Bow's notation labels the spaces between the forces, and each force is the line that joins those letters in the force diagram. State the scale of that diagram, or a length on it is not a force. For a simple frame, find the reactions first, then work joint by joint from a joint with only two unknown members. Say whether each member is in tension or in compression. A shear force diagram jumps by the size of a point load and changes gradually under a distributed load. For a simple beam, the bending moment turns where the shear crosses zero. The centre of gravity of a triangle is where the medians meet. A composite lamina is split into simple shapes, and you take moments of area. Do not invent a load the question did not give.

5. 5. Building drawing or mechanical drawing

   Offer the option you are entered for. Building drawing includes foundations and floors, doors, windows and arches, stairs, roofs, and working drawings: a plan, the elevations asked for, and a section, with the scale stated. Rise is the vertical part of a step. Going is the horizontal part. Name the roof members you can see, such as a rafter, a tie, a wall plate and a ridge. Do not invent a thickness or a millimetre. Mechanical drawing includes orthographic views of machine parts, sectional views, conventional screw threads, and an assembly with item numbers and a parts list. A cutting plane shows where you cut, and the arrows show the direction you look. Hatch the material that is actually cut. Do not hatch a shaft, a bolt, a nut, a rib or a web when the cut runs along its length. Adjacent parts hatch in opposite directions. A thread on an orthographic view is the conventional pair of lines, not a pictorial helix, unless the question asks for the helix. Sketch means freehand and in proportion. Draw means instruments, construction, and the scale the question states.

WASSCE syllabusPast questions with answersWASSCE Technical Drawing past questionsLines and letteringGeometrical constructionOrthographic projectionPictorial drawingSections and developmentsTechnical drawing basicsDrawing from observationBECE Career Technology tipsWASSCE Physics tipsWASSCE Visual Arts tips

Constructions, sketches, and the drawing

A construction mark is for a method a marker can see. A drawing mark is for a view that follows the brief. A neat outline with no construction is hard to credit when the question said construct.

1. 1. Match the command

   Construct means show the construction. Draw means the finished view, to the scale, with instruments. Sketch means freehand, in proportion, with the right line types. Project means the views line up. Determine, on a vector question, means the graphical answer, with the scale of the force diagram stated. A definition does not answer a question that asked for a construction.

2. 2. Leave the method visible

   Keep construction light, and darken the required outline at the end. A tangent, a locus, a true shape or a development with the construction erased cannot earn the method marks. If the question tells you to remove construction, follow that instruction and not this one.

3. 3. State the scale and the angle

   Write the scale the question gives, and use it for every length. Write first angle or third angle in the title block, and do not mix them. On a force diagram, write the scale that turns a length into a force. A figure you made up will not match the drawing.

4. 4. Label what the marker has to find

   Name the views: front, plan, end, auxiliary. Name the cutting plane. On a frame, name the member and say tension or compression. On a building section, name the parts the question asked for. A heap of notes at the side is not a label.

5. 5. On paper 3, obey the choice

   Do the compulsory sketch. Then do one other sketch if the rubric asks for one. Then draw either the building question or the mechanical question, not both. A beautiful drawing of the option you do not offer has not answered your paper.

6. 6. Leave out the invented size

   A wall thickness, a rise, a tolerance or a force that the question did not give is not a result. Use the figure on the paper. If no figure is given, show the construction and the principle.

WASSCE exam tipsPast questions with answersTechnical drawing basics

How to use the time

The clock is on the timetable and on the front of the paper. This page does not copy a duration. The habit is the same on any length of paper.

1. 1. Read the front before you draw

   Note how many constructions you may answer, and that paper 3 has a compulsory sketch plus one drawing. School candidates and private candidates follow the paper in front of them.

2. 2. Start the hardest construction while you are calm

   A locus, a development or a vector diagram gets worse when you rush it. Give it a clean sheet area. An unfinished second attempt does not replace a required question you left blank.

3. 3. Plan the sheet before you commit an outline

   Leave room for the title block, the border, and the views you must project. A drawing that runs off the sheet has not been planned. Draw the main view first, then project. Keep construction light until the shape is right.

4. 4. Treat paper 3 as its own paper

   Do the compulsory sketch first. Then the one drawing for your option. Do not start the other option because it looks shorter. Sketch means freehand. The formal drawing means instruments.

5. 5. Leave a short check at the end

   Darken outlines. Add centre lines. Check that dimensions agree. Check that you stated the scale and the angle of projection. The exam tips cover the morning of the paper. This page does not copy a duration.

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A short way to revise

Rotate the papers. A week of instruments with no vector work, or a week of sketches with no formal drawing, leaves part of the examination cold.

1. 1. Give each paper a turn

   One session for objective items, one for a plane or solid construction from memory, one for a vector question if you sit the Ghana paper, and one for the option you offer: a building section or a mechanical assembly. Do the compulsory sketch from memory as well. Do not save paper 3 for the night before.

2. 2. Close the book and construct

   Bisect an angle. Draw a tangent to a circle. Develop a truncated prism using true lengths. Project a plan in the angle the question names. Then check which construction line you forgot, and which view you placed on the wrong side.

3. 3. Reject the wrong options

   On an objective item, say why the other options fail. A plan placed below the front view is first angle, not third angle. A hidden edge drawn as a thick outline is a reason to reject an option, not a detail to ignore.

4. 4. Have the explanation marked

   Anna marks WASSCE answers on glearn. Kevin is the coach on BECE practice. Write the steps of a construction in sentences and have them marked point by point. Practise with Kevin and Anna on glearn.now. The first questions need no account. Compare your drawing with the method, not only with a picture that looks tidy.

5. 5. Keep Technical Drawing inside the wider plan

   The revision plan orders the weeks across every subject you sit. Physics uses forces and moments in a different way, and it is not this paper. Career Technology at BECE has a drawing strand, and it is not this paper. General Knowledge in Art is not this paper. The programme guide says what a technical programme is for. This page does not copy a date.

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Mistakes chief examiners keep returning to

WAEC chief examiners write a report after a sitting. This page describes the habits in general. It does not quote a report, and it does not give a figure.

1. 1. First angle mixed with third angle

   The plan is either below the front view or above it. The end view is either on the opposite side or on the same side. One sheet uses one system. The title block says which.

2. 2. The wrong line, or no centre line

   An outline drawn thin, a hidden edge drawn solid, and a hole with no centre line are wrong even when the shape is right. Construction that is as dark as the outline hides the answer.

3. 3. A construction with the method erased

   A locus, a tangent, a true shape or a development needs the construction. A fair curve alone has not shown the method, unless the question told you to remove it.

4. 4. Dimensions that do not agree

   A chain of sizes that does not match the overall size, or a figure that ignores the stated scale, cannot all be right. Do not invent a millimetre the question did not give.

5. 5. Both options attempted

   Building drawing and mechanical drawing are alternatives where the rubric says choose one. Two unfinished drawings do not replace the one drawing you were meant to finish. The compulsory sketch still has to be done.

6. 6. A vector answer with no nature and no scale

   A force diagram without a scale is a picture. A member without tension or compression is unfinished. A shear force diagram that ignores a point load has not followed the question.