r=6x

The area of a circle is equal to Pi π times the radius r squared.

π⋅(radius)2

Substitute in the value of the radius r=6 into the formula for the area of a circle. Pi π is approximately equal to 3.14.

π⋅62

Raise 6 to the power of 2.

π⋅36

Move 36 to the left of π.

36πx2

Find the Area circle (6x)