Chapter 9 - Unit 2 - Area & Circumference of Circles

The area of a circle is

A = πr^2

where: A = area, r = radius

The circumference of a circle is

C = 2πr or C = πd

where: C = circumference, r = radius, d = diameter

Find each measurement.
1. the circumference of circle B

d = 6/π cm.

π * 6/π

c = 6

2. the area of circle R in terms of π

r = 5 m.

a = π25

3. the area of circle Z in terms of π

d = 22 ft.

a = π121

4. the circumference of circle T in terms of π

r = 10 in.

c = π20

C = 2πr

5. the circumference of circle X in which A = 49π in.^2

C = 44

A = 49π

C = 2π(7)

6. the radius of circle Y in which C = 48π cm.

r = 9