Question

Find the circumference

Answer 1

circumference = 2 X PI X r

orange circle r = 5cm 
circumference = 2 x 3.14 x 5 = 31.4 cm

blue circle r = 5+5 = 10
circumference = 2 x 3.14 x 10 = 62.8 cm

Answer 2

Hey there!

We'll start with the outer circle.

Circumference is defined as 2πr, which is 2π times the radius. If the outer circle has a radius of 5, we plug in:

2π(5) = 10π

For the outer circle, we have a radius of 5 as well, therefore we also get:


2π(5) = 10π


For our total circumference, we get 20π

Hope this helps!