4400 Higher November 2009 Paper 3 Q18
18 In the diagram, a sector of a circle of radius 12 cm is shaded.
The area of the sector is \(112\pi\) cm2.
Calculate the value of \(x\).
Diagram NOT accurately drawn
(4)
| Scheme | Marks |
|---|---|
| \(x/360 \times \pi \times 12^2 = 112\pi\) | M2 |
| \((x =)\ 112\pi \times 360/12^2\pi\) oe | M1 |
| 280 | A1 |
| (4) | |
| (4 marks) |
Notes
M2: M1 for \(x/360 \times \pi \times 12^2\) (\(= 0.4\pi x\) or \(1.256...x\))
Alternative
\(144\pi\) M1
\(112\pi/144\pi\) (= 7/9) or \(32\pi/144\pi\) (= 2/9) M1
7/9 × 360 or 2/9 × 360 = 80 M1