Make r the subject of the formula

S=4TIr^2

To make r the subject of the formula, we can follow the following steps:

1. Divide both sides of the equation by 4T i.e.,
S / (4T) = Ir^2.

2. Divide both sides of the equation by I i.e.,
(S / (4T)) / I = r^2.

3. Take the square root of both sides of the equation i.e.,
√((S / (4T)) / I) = r.

Therefore, r is the subject of the formula.