Question

The surface area of a ball is 3,600x square millimeters. What is the ball's radius?

Recall the formula SA=42
15 mm
21 mm
30 mm
450 mm

Answer 1

C. 30 mm

the person above was correct.

Answer 2

30 mm

Explanation:

Given,

Surface Area of ball =
`3600\pi\ mm^2`

We have to find out the radius of the ball.

Solution,

Since the formula of Surface area is 4 times π times square of the radius.

We can frame it as;

`S.A.=4*\pi* r^2`

Now on substituting the values, we get;

`4*\pi* r^2=3600\pi`

On dividing both side by 'π' using division property, we get;

`(4*\pi* r^2)/(\pi)=(3600\pi)/(\pi)\\\\4* r^2=3600`

On dividing both side by '4' using division property, we get;

`(4* r^2)/(4)=(3600)/(4)\\\\r^2=900`

Now taking square root on both side, we get;

`√(r^2) =√(900)\\ \\r=30\ mm`

Hence The radius of the ball is 30 mm.