What is the circumference and the area of a circle that has a diameter of 35 cm?

2 Answers
Jan 7, 2016

Circumference = 110cm110cm and Area = 962.11cm^2962.11cm2.

Explanation:

Diameter is twice radius : d=2rd=2r.

therefore r=d/2=35/2=17.5cm.

Circumference : C=2pir=35pi=110cm.

Area : A=pir^2=pi*17.5^2=962.11cm^2.

Jan 7, 2016

Circumference = 109.96cm (2 sig. fig.)
Area = 962.11 cm^2 (2 sig. fig.)

Explanation:

The radius of a circle is half its diameter. The radius of a circle with a diameter of 35cm is 17.5cm.

The circumference of a circle is found by 2pir. So that would be 2*pi*17.5 which would be equal to 109.96cm (2 sig. fig.).

The area of a circle is found by pir^2. So that's pi*17.5^2 which is equal to 962.11cm (2 sig.fig.).