266.9=3.14(5)r^2

Solution for 266.9=3.14(5)r^2 equation:

Simplifying
266.9 = 3.14(5) * r2

Multiply 3.14 * 5
266.9 = 15.7r2

Solving
266.9 = 15.7r2

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Add '-15.7r2' to each side of the equation.
266.9 + -15.7r2 = 15.7r2 + -15.7r2

Combine like terms: 15.7r2 + -15.7r2 = 0.0
266.9 + -15.7r2 = 0.0

Add '-266.9' to each side of the equation.
266.9 + -266.9 + -15.7r2 = 0.0 + -266.9

Combine like terms: 266.9 + -266.9 = 0.0
0.0 + -15.7r2 = 0.0 + -266.9
-15.7r2 = 0.0 + -266.9

Combine like terms: 0.0 + -266.9 = -266.9
-15.7r2 = -266.9

Divide each side by '-15.7'.
r2 = 17

Simplifying
r2 = 17

Take the square root of each side:
r = {-4.123105626, 4.123105626}