Higher November 2017 Paper 1 Q19
19 The diagram shows a triangle and a trapezium.
Not drawn accurately
Prove that \(\quad a = b\) [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(a + 65 + 115 + c = 360\) or \(\;b + c = 180\) | M1 | oe oe |
| \(a + c = 180\) and \(\;b + c = 180\) and \(\;a = b\) | A1 | oe eg \(c = 180 - a\) \(b = 180 - (180 - a)\) \(= a\) |
| angles at a point and (co)interior angles | A1 |
Additional guidance
Accept angles round a point for angles at a point
Accept allied angles for interior angles