SOLUTION: I have this math problem. The area of a circle is 25 square meters. Find the radius of the circle. What I don't understand is how to solve for r, and the answer has numbers to t

Question 50936This question is from textbook Algebra 1 - Saxon
: I have this math problem. The area of a circle is 25 square meters. Find the radius of the circle. What I don't understand is how to solve for r, and the answer has numbers to the hundredth place... This question is from textbook Algebra 1 - Saxon

Found 2 solutions by Earlsdon, tutorcecilia:
Answer by Earlsdon(6098) (Show Source):
You can put this solution on YOUR website!
Remember that the area of a circle is given by:
To solve for r (radius), divide both sides by
Now take the square root of both sides.

If A = 25 sq. meters, and = 3.14 (Approximately)

meters, rounded to the nearest thousandth.

Answer by tutorcecilia(2144) (Show Source):
You can put this solution on YOUR website!
Area of a circle = (pi)(r^2) [The formula for the area of a circle]
25m^2=(pi)(r^2) [Plug-in the values]
25/pi=(pi)(r^2)/(pi) [Solve for the radius (r)]
25/pi=r^2

2.820947=r [Round to the nearest 100th place]
2.82=r
.
Check that (r=2.82) by plugging it back into the original equation:
Area of a circle = (pi)(r^2)
25=(pi)(2.82^2)
25 is equivelent to 24.9832 [Close enough]