Question

What is the value of the radius of the following circle with an area of 154 cm2?

Answer 1

The area of ANY circle is (π) · (radius²).

So ...

(π) · (radius²) = 154 cm²

radius² = (154 cm²) / (π)

radius² = 49.02 cm²

radius = √(49.02 cm²)

radius = 7 cm

Answer 2

`\boxed{\sf Radius \ of \ circle \ (r) = 7 \ cm}`

Given:

Area of circle = 154 cm²

To Find:

Radius of circle (r)

Step-by-step explanation:

`\bold{Area \: of \: circle = \pi r^2}`

`\sf \implies \pi {r}^(2) = 154 \\ \\ \sf \implies {r}^(2) = (154)/(\pi) \\ \\ \sf \implies {r}^(2) = (154)/( (22)/(7) ) \\ \\ \sf \implies {r}^(2) = (154 * 7)/(22) \\ \\ \sf \implies {r}^(2) = (1078)/(22) \\ \\ \sf \implies {r}^(2) = 49 \\ \\ \sf \implies {r}^(2) = {7}^(2) \\ \\ \sf \implies r = \sqrt{ {7}^(2) } \\ \\ \sf \implies r = 7 \: cm`