4MA0 Higher June 2016 Paper 3 Q19
19
Diagram NOT accurately drawn
\(A\), \(B\), \(C\) and \(D\) are points on a circle, centre \(O\).
Angle \(DAB\) = 75°
Angle \(DBC\) = 27°
Work out the size of angle \(ODC\).
(4)
| Scheme | Marks |
|---|---|
| Angle \(DCB\) = 180 − 75 (=105) | M1 |
| Angle \(DOB\) = 2 × 75 (=150) | M1 |
| E.g. (180 – 105 – 27) + (180 – 150)÷2 or 360 – (150 + 105 + 27 + (180 – 150)÷2) | M1 |
| 63 | A1 |
| (4) |
Notes
M1: Use of opposite angles in a cyclic quadrilateral sum to \(180^\circ\)
M1: Use of angle at centre is twice angle at circumference
M1: Complete method