Find the length of ${\text{arc ACB}}$.

Find the perimeter of the shaded region.

correct substitution     (A1)

eg$\;\;\;10(1.2)$

$ACB$ is $12{\text{ (cm)}}$     A1     N2

[2 marks]

valid approach to find major arc     (M1)

eg$\;\;\;$circumference $- {\text{AB}}$, major angle ${\text{AOB}} \times {\text{radius}}$

correct working for arc length     (A1)

eg$\;\;\;2\pi (10) - 12,{\text{ }}10(2 \times 3.142 - 1.2),{\text{ }}2\pi (10) - 12 + 20$

perimeter is $20\pi  + 8\;\;\;( = 70.8){\text{ (cm)}}$     A1     N2

[3 marks]

Total [5 marks]

Most candidates were able to find the minor arc length. Similarly most candidates successfully found the major arc length in part b) but did not go on to add the two radii. Quite a few candidates worked with decimal approximations, rather than in terms of $\pi$.

Most candidates were able to find the minor arc length. Similarly most candidates successfully found the major arc length in part b) but did not go on to add the two radii. Quite a few candidates worked with decimal approximations, rather than in terms of $\pi$.