Determine the circumference of a circle with a diameter of 13. Round your answer to the tenths place.

a.

132.7 units

c.

530.9 units

b.

40.8 units

d.

81.7 units

The formula for circumference is 2pi*r. To find r (radius of the circle) you have to divided the diameter by 2. 13 divided by 2 is 6.5. Then multiple 6.5 by 2 then by 3.14. You should then get 40.8 as your answer.

I think its 40.8 i think