## anonymous one year ago What is the formula to find the circumference of a circle?

1. anonymous

$C=2πr$

2. anonymous

or C=πd

3. anonymous

@tbeneka , that's not one of my choices :( C=2pi*d C=pi*d C=pi*r

4. anonymous

sorry, just saw that.. thanks! :)

5. Empty

If you were curious this formula really comes from the definition of $$\pi$$. You see if you take any circle and measure its circumference and measure it's diameter these depend on how big of a circle you pick. However if you divide the circumference by the diameter, you always get a constant value, and that value is $$\pi$$!

6. anonymous

@Empty Thanks! :D