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

2 Answers
Jan 7, 2016

Circumference = #110cm# and Area = #962.11cm^2#.

Explanation:

Diameter is twice radius : #d=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.).