In the diagram above, O is the center of the circle with radius 10cm, and ∠ABC = 30°. Calculate, correct to 1 decimal place, the length of arc AC [Take π = 22/7]
-
A.
5.2cm -
B.
10.5cm -
C.
13.2cm -
D.
20.6cm -
E.
31.4cm
Correct Answer: Option B
Explanation
In the figure, < AOC = 2 x < ABC = 60° (angle subtended at the centre)
(therefore) Arc AC = (frac{60}{360} times 2 times 10 times 3.14)
= (frac{31.4}{3})
= 10.466 cm (approxeq) 10.5 cm