Higher November 2017 Paper 1 Q10
10 Three identical isosceles triangles are joined to make this trapezium.
Each triangle has base \(b\) cm and perpendicular height \(h\) cm
Not drawn accurately
(a) Work out an expression, in terms of \(b\) and \(h\), for the area of the trapezium.
Give your answer in its simplest form. [2 marks]
(b) This diagram shows the same trapezium.
Not drawn accurately
\(b : s \;=\; 2 : 3\)
Work out an expression, in terms of \(b\), for the perimeter of the trapezium. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{1}{2}(b + 2b)h\) or \(3 \times \dfrac{1}{2}bh\) | M1 | oe |
| \(1.5bh\) or \(\dfrac{3}{2}bh\) or \(\dfrac{3bh}{2}\) or \(1\dfrac{1}{2}bh\) | A1 | accept \(hb\) for \(bh\) |
Additional guidance
| Correct expression with \(\times\), \(\div\) or brackets | M1A0 |
| Condone units within expressions for M1 only | |
| Condone the expression given within a formula eg \(A = 1.5hb\) | M1A1 |
| Condone correct expression stated and then equated to a value or with values substituted | M1A1 |
| Answer | Mark | Comments |
|---|---|---|
| \(3b + 2s\) or \(3b = 2s\) or \(4s\) | M1 | oe |
| \(6b\) | A1 | oe eg \(b + b + b + b + b + b\) |
Additional guidance
| Condone the expression given within a formula eg \(P = 6b\) | M1A1 |