4MA0 Higher June 2014 Paper 3 Q9

EdexcelHigherOld spec3 marksPrisms

Triangular prism of length 8 cm; the cross-section is an isosceles triangle with sides 13 cm, 13 cm and 10 cm and perpendicular height 12 cm

Diagram NOT accurately drawn

The diagram shows a prism.
The cross-section of the prism is an isosceles triangle.
The lengths of the sides of the triangle are 13 cm, 13 cm and 10 cm.
The perpendicular height of the triangle is 12 cm.
The length of the prism is 8 cm.

Work out the total surface area of the prism.

(3)

Mark scheme

Scheme	Marks
0.5 x 10 x 12 (= 60) or 13 x 8 (= 104) or 8 x 10 (= 80)	M1
0.5 x 10 x 12 (= 60) and 0.5 x 10 x 12 (= 60) and 13 x 8 (= 104) and 13 x 8 (= 104) and 8 x 10 (= 80) or 2 x “60” and 2 x ”104” and “80”	M1
408	A1
	(3 marks)

Notes

M1: One correct face

M1: dep on M1 above (exactly 5 correct faces )

A1: Award M0A0 for 0.5 x 10 x 12 × 8 and
M0A0 for 0.5 x 10 x 12 = 60 followed by 60 × 8, etc