A chord subtends an angle of 120o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take (pi = frac{22}{7})]
-
A.
14(frac{1}{3})cm -
B.
12(frac{5}{6})cm -
C.
8(frac{1}{7})cm -
D.
7(frac{1}{3})cm
Correct Answer: Option A
Explanation
perimeter of minor sector
2r + (frac{theta}{360} times 2 pi r)
= 2 x 3.5 + (frac{120^o}{360^o} times 2 frac{22}{7} times 3.5)
= 7 + (frac{154}{21})
= 7 + 7.33
= 14.33
= 14(frac{1}{3})cm