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

5cm = r

Step-by-step 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

The Radius = 5

Step-by-step 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!