Respuesta :

31.4/3.14=10
10/2=5
5*5*3.14= 78.5 cm square
The circumference of a circle is found by 2(pi)•r. To find r, set this equal to the circumference they gave you.

31.4=2pi•r

Divide by 2pi

r=4.997

The area of a circle is given by pi•r^2

A=pi(4.997)^2

A=78.460 cm^2