Calculate the length in cm. of the area of a circle of diameter 8cm which subtends an angle of 22\(\frac{1}{2}\)
o at the centre of the circle
A. 2\(\pi\)
B. \(\pi\)
C. \(\frac{2}{3}\)
D. \(\frac{\pi}{2}\)
Correct Answer: D
Explanation
Diameter = 8cm
∴ Radius = 4cm
Length of arc = \(\frac{\theta}{360}\) x 2 \(\pi\)r but Q = 22\(\frac{1}{2}\)
∴ Length \(\frac{22\frac{1}{2}}{360}\) x 2 x \(\pi\) x 4
= \(\frac{22\frac{1}{2} \times 8\pi}{360}\)
= \(\frac{180}{360}\)
= \(\frac{\pi}{2}\)
