Question

Suppose the radius of a circle is 8. What is its circumference? Enter either an exact answer or use pi or use 3.14 for pi and enter your answer as a decimal.

Answer 1

Hey there!

In this answer, we will use 3.14 for pi.

When we say circumference, we mean the distance around the circle. That means that we're looking to find the distance around this circle with a radius of 8. The formula for circumfrence is:

2πr = C

However, there's also another formula, which is equivalent:

πD = C

This second formula means that pi times the diameter is equal to the circumference of the circle. Here's why it works:

When you say radius, you mean distance from one side of the circle to the middle. When you say diameter, you mean distance from one side of the circle to the other side of the circle. Therefore, when you multiply radius by 2, you get the diameter. That's why this works. Instead of having the 2πr, you just multiply the 2 and the r to get D, because two times the radius equals the circumference. We'll use that formula.

Since we have the radius, as stated earlier, we need to multiply it by two to get the diameter. 2 times 8 equals 16. Therefore, we have:

C = π(16)
C = 3.14(16)

C = 50.24 units squared.

Hope this helps!

Answer 2

8*3.14=  25.12 * 2= 
Circumference= 50.24