20=r*r*12

Solution for 20=r*r*12 equation:

Simplifying
20 = r * r * 12

Reorder the terms for easier multiplication:
20 = 12r * r

Multiply r * r
20 = 12r2

Solving
20 = 12r2

Solving for variable 'r'.

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

Add '-12r2' to each side of the equation.
20 + -12r2 = 12r2 + -12r2

Combine like terms: 12r2 + -12r2 = 0
20 + -12r2 = 0

Add '-20' to each side of the equation.
20 + -20 + -12r2 = 0 + -20

Combine like terms: 20 + -20 = 0
0 + -12r2 = 0 + -20
-12r2 = 0 + -20

Combine like terms: 0 + -20 = -20
-12r2 = -20

Divide each side by '-12'.
r2 = 1.666666667

Simplifying
r2 = 1.666666667

Take the square root of each side:
r = {-1.290994449, 1.290994449}