Mathematics for IGCSE & O level - Equations (Section 7 - No. 7)
The formula for the area of a circle is A = πr². If we want to make 'r' the subject, the first step is:
Divide both sides by π
Multiply both sides by π
Take the square root of both sides
Add π to both sides
Explication
To isolate r², divide both sides by π first: A/π = r²