1MA0 Foundation November 2014 Paper 2 Q15
*15
Diagram NOT accurately drawn
\(ABC\) is a straight line.
Angle \(BCD = 38^\circ\)
The reflex angle \(BDC = 250^\circ\)
Work out the size of the angle marked \(x\).
Give reasons for your answer. (4)
| Answer | Mark | Notes |
|---|---|---|
| \(148^\circ\) | 4 | M1 for (angle \(BDC =\)) \(360 - 250\) (= 110) M1 (dep) for \(180 - (180 - \text{‘}110\text{’} - 38)\) (= 148) or for \(\text{‘}110\text{’} + 38\) (= 148) C2 (dep on M2) for \(x = 148\) with full reasons, relevant to the complete correct method used, for example: Angles at a point add up to \(360^\circ\) and angles in a triangle add up to \(180^\circ\) and angles on a straight line add up to \(180^\circ\); Or Angles at a point add up to \(360^\circ\) and exterior angle of a triangle is equal to the sum of the interior opposite angles or (C1 (dep on at least M1) for one reason relevant to correct method) |