Higher June 2019 Paper 2 Q12
12 \(OAB\) is a sector of a circle with centre \(O\) and radius 7 cm.
The area of the sector is 40 cm2
Calculate the perimeter of the sector.
Give your answer correct to 3 significant figures. (4)
| Answer | Mark | Mark scheme |
|---|---|---|
| 25.4 | P2 | for finding the size of the angle eg \(\dfrac{40 \times 360}{\pi \times 7^2}\) (= 93.5(4..)) or for working with proportion, eg \(\dfrac{40}{49\pi}\) (= 0.259(8…) or 0.26) or \(\dfrac{49\pi}{40}\) (= 3.84(8…) or 3.85) |
| (P1 | for finding the area of the circle eg \(\pi \times 7^2\) (= 153(.938..) or 154)) | |
| P1 | (dep on P2) for a process to find the arc length, eg \(\dfrac{\text{``}93.5(4...)\text{''}}{360} \times \pi \times 2 \times 7\) (= 11.4(28…)) or \(\dfrac{40}{49\pi} \times \pi \times 2 \times 7\) (= 11.4(28…)) or \(\pi \times 2 \times 7 \div \dfrac{49\pi}{40}\) (= 11.4(28…)) | |
| A1 | for answer in the range 25 to 25.44 |
Additional guidance
May be embedded
If an answer is shown in the range in working and then incorrectly rounded award full marks.
Accept \(\dfrac{178}{7}\)