Question

Find the area and circumference of the following circle. (Round answer to the nearest hundredth.) r = 4.5 cm

Answer 1

A = 63.6 C = 28.3

This is because
A = π x 4.5^2 = 63.6
C = 2 x π x 4.5 = 28.3

Answer 2

Given: radius of the circle(r) = 4.5 cm

Area of the circle(A) is given by:

`A = \pi r^2` ......[1]

where, r is the radius of the circle.

Substitute the given values in [1] and
`\pi = 3.14` we have;

`A = 3.14 \cdot (4.5)^2 = 3.14 \cdot 20.25= 63.585 cm^2`

⇒Area of the circle to the nearest hundredth is,
`63.59 cm^2`

Circumference(C) of the circle is given by:

`C= 2 \pi r`

Substitute the given values we have;

`C = 2 \cdot 3.14 \cdot 4.5`

Simplify:

C = 28.26 cm

⇒Circumference of the circle to the nearest hundredth is, 28.26 cm