Question

Please help me in number 20 please I need it ASAP

Answer 1

`r=\sqrt{(A)/(\pi)}`

Explanation:

Given:

The area 'A' of a circle with radius equal to 'r' is given as:

`A=\pi r^2`

In order to rewrite the given formula in terms of radius 'r', we need to isolate 'r'.

Dividing both sides by π, we get:

`(A)/(\pi)=(\pi r^2)/(\pi)`

As
`(\pi)/(\pi)=1`, the above equation becomes:

`r^2=(A)/(\pi)`

Taking square root both the sides, we get:

`√(r^2)=\sqrt{(A)/(\pi)}\\r=\sqrt{(A)/(\pi)}`

We neglect the negative result while taking square root as the radius can't be a negative number.

Thus, the formula for radius 'r' in terms of area 'A' is given as:

`r=\sqrt{(A)/(\pi)}`