Find ${\rm{P}}\widehat {\rm{R}}{\rm{Q}}$ .

Find the area of triangle PQR.

choosing sine rule     (M1)

correct substitution $\frac{{\sin R}}{7} = \frac{{\sin 75^\circ }}{{10}}$     A1

$\sin R = 0.676148 \ldots$

${\rm{P}}\widehat {\rm{R}}{\rm{Q = 42}}{\rm{.5}}^\circ$     A1     N2

[3 marks]

$P = 180 - 75 - R$

$P = 62.5$     (A1)

substitution into any correct formula     A1

e.g. ${\text{area }}\Delta {\text{PQR}} = \frac{1}{2} \times 7 \times 10 \times \sin ({\text{their }}P)$

$= 31.0$ (cm²)     A1     N2

[3 marks]

This question was well done with most students using the law of sines to find the angle.

In part (b), the most common error occurred when angle R or 75 degrees was used to find the area. This particular question was the most common place to incur an accuracy penalty.