The area of a circle is 38.5cm2. Find its diameter [take (pi = frac{22}{7})]
-
A.
22cm -
B.
14cm -
C.
7cm -
D.
6cm
Correct Answer: Option C
Explanation
(pi r^2 = 38.5\
frac{}{} = r^2 = 38.5\
r^2 = frac{38.5 times 7}{22}\
r = sqrt{12.25} = 3.5\
diameter = 2r = 2 times 3.5 = 7cm)