1MA0 Foundation November 2012 Paper 1 Q19
*19
Diagram NOT accurately drawn
Work out the value of \(y\).
Give reasons for your answer. (4)
| Working | Answer | Mark | Notes |
|---|---|---|---|
| \(360 - 200 - 90\) (=70) \((180 - \text{`}70\text{'}) \div 2\) angles at a point add to 360°, angles in a triangle add to 180°, base angles of an isosceles triangle are equal | \(y = 55\) reasons | 4 | M1 for \(360 - 200 - 90\) oe M1 for \((180 - \text{`}70\text{'}) \div 2\) Reasons: angles at a point add up to 360° angles in a triangle add up to 180° base angles of an isosceles triangle are equal C2 for \(y = 55^\circ\) and all correct reasons Note: An answer of 55° alone, is not enough; \(y = 55^\circ\) must be explicitly stated or clearly shown on the diagram (C1 for one correct reason) Note: the award of any C mark is dependant upon the award of at least M1 |