Question

The area (A of a circle with a radius of ris given by the formula A = 772 and its diameter (d) is given by d = 27. Arrange the equations in

the correct sequence to rewrite the formula for diameter in terms of the area of the circle.
d² = 24
d = VZA
A = 41d2
d =
4A
d2

Answer 1

A = πr² ← r is the radius and r = \frac{1}{2} d ← d is the diameter

Hence

π (\frac{1}{2} d)² = A, that is

\frac{d^2\pi }{4} = A ( multiply both sides by 4 )

d²π = 4A ( divide both sides by π )

d² = \frac{4A}{\pi } ( take the square root of both sides )

d = \sqrt{\frac{4A}{\pi } }