Kevin designs sprinkler system for his yard. One rotation of the sprinkler waters a circle with an area of 225(pi) square feet. What is the radius, r, of the circle the rotating sprinkler waters?

a) 15 ft
b) 25 ft
c) 30 ft
d) 47 ft
Answer - A
Why?:
A = (pi) x r(2 to the second power)
A = 225 x 15 (2 to the second power)
15 x 15 = 225

2 answers

pi r^2 = 225 pi
r^2 = 225
r = 15
im correct :)

thanks