Question

Given the radius and area of the circle, calculate the angle at the centre of the circle.

Radius : 21 m
Area of the circle : 27.72 m^2​

Answer 1

`\theta = 7 .2\degree`

Explanation:

`area = (\theta)/(360) * \pi {r}^(2) \\ 27.72 = (\theta)/(360) * \pi * {21}^(2) \\ 27.72 = (\theta)/(360) * \pi * 441 \\ (27.72 * 360)/(441\pi) = \theta \\ (9979.2)/(1385.4) = \theta \\ \\ 7 .2\degree = \theta`