Question

A circle has a radius of 7ft. What is its circumference?Use 3.14 for it, and do not round your answer. Be sure to include the correct unit in your answer.7ft

Answer 1

The circumference of a circle with radius r is given by:

$C=2\pi\cdot r$

The area of a circle with raidus r is given by:

$A=\pi\cdot r^2$

Then for a cirlce of radius 7ft we have a circumference of:

$C=2\pi\cdot7ft=2\cdot3.14\cdot7ft=43.96ft$

And an area of:

$A=\pi\cdot(7ft)^2=3.14\cdot49ft^2=153.86ft^2$

Then the answers are:

Circumference: 43.96ft

Area: 153.86ft²