Question

The area of a circle is 78.5 cm² . Find the lenght of the radius of a circle . Use π = 3.14

Answer 1

The Radius= 5

Explanation:

First since you divide the area by 3.14, which should get you 25. Then your supposed to find the square root of 25 OR in other terms find 2 numbers when multiplied equal 25. That is 5.

To check your answer:

To check if this is correct simply find the area by using the radius.

The formula is radius multiplied by itself then multiplied by pi/3.14.

5x5=25, 25x3.14=78.5

There you go! 78.5 is the area!

Answer 2

5cm = r

Explanation:

The area of a circle is given by

A = pi r^2

78.5 = 3.14 r^2

Divide each side by 3.14

78.5/ 3.14 = r^2

25 = r^2

Take the square root of each side

sqrt(25) = sqrt(r^2)

5 = r