Question

The area if the of a circle is 111.6 square centimeters. What is the diameter?

Answer 1

The equation for a circle's area is \pi r^2. and the equation for the diameter is 2\pi r . lets find r. we have 111.6=3.14*r^2. divide by 3.14 on both sides. that makes 36=r^2 take the square root of both sides. r=6. 
now we find the diameter. 2\pi r=2*3.14*6=3.14*12 which is approximately 38.68

Answer 2

The diameter of the circle would be 11.9203