Question

A circle has a circumference of 22 cm. What is the diameter, area, and radius. Round to the nearest tenth.

Answer 1

The circumference is 22
Circumference = 2πr 
22 = 2πr
It's the same thing as π*diameter
22 = πd
divide both sides by π to isolate d
d, or the diameter, equals 7.0028175 cm, or approx. 7 cm
the radius is half of the diameter so it is 3.50140875, or approx. 3.5 cm
the area of the circle is 
A = π r²
A = π (3.5)²
A = π (12.25)
A = 38.4845
The area equals approximately 38.5 cm^2.

Hope this helps!