In the diagram above, O is the centre of the circle. Reflex angle XOY = 210º and the length of the minor arc is 5.5m. Find, correct to the nearest metre the length of major arc.
-
8m
- 9m
- 10m
- 13m
The correct answer is: A
Explanation
Length of arc = \(\frac{Ø}{360} \time 2\pi\)
5.5 = \(\frac{360 - 210}{360}\) x 2 x \(\frac{22}{7}\)
\(\frac{ 5.5 \time 360\times7}{150\times2\times22}\) = 2.1
length of major arc = \(\frac{210}{360}\) x 2 x \(\frac{22}{7}\) x 2.1
7.7m ≈ 8m