Intermediate June 2019 Unit 2 Q14
14. \(PQR\) is a right-angled triangle.
\(PR = 16{\cdot}7\) cm, \(QR = 9{\cdot}6\) cm.

Diagram not drawn to scale
Calculate the size of \(Q\widehat{P}R\). [3]
| Scheme | Marks | Comments |
|---|---|---|
| sin (QPR) = \(\dfrac{9{\cdot}6}{16{\cdot}7}\) | M1 | |
| (QPR =) sin−1 (9.6/16·7) or sin−1 (0·57..) | m1 | Implies M1. |
| = 35·1(°) or 35·09(°) or 35·089(…°) | A1 | Allow any answer that rounds to 35(°) |
Alternative method.
| Scheme | Marks | Comments |
|---|---|---|
| Correct use of ‘two-step’ method. | M2 | A partial trigonometric method is M0. |
| (x) = 35·1(°) or 35·09(°) or 35·089(…°) | A1 | Allow any answer that rounds to 35(°) |