20 The diagram shows an equilateral triangular prism. Each side of the equilateral triangle is 6 cm and the length of the prism is 7 cm.
Not to scale
(a) Draw an accurate plan view of the prism on the one-centimetre square grid below.
[3]
(b) Draw an accurate front elevation of the prism on the one-centimetre isometric grid below.
[2]
Mark scheme (a)
Answer
Marks
Part marks and guidance
7 by 6 rectangle (not dashed) with correct dividing line
3
B2 for a 7 by 6 rectangular outline or for any rectangular outline correctly splitting the shorter side in half by one line or B1 for any rectangular outline
Outline is not a square, accept horizontally or vertically, accept freehand and for accuracy mark intention, condone dashed centre line
If the diagram uses the grid edges and the line is not drawn SC2 for an otherwise correct answer or SC1 for a 7 by 6 rectangular outline
Mark scheme (b)
Answer
Marks
Part marks and guidance
Equilateral triangle with side 6 cm and no extra lines
2
B1 for equilateral triangle but the incorrect size or a correct equilateral triangle with one extra line
Accept good freehand and for accuracy mark intention
