# Why is pi = 180 degrees radians?

##### 1 Answer

May 14, 2015

Think of a circle.

Now think of half of it and focus on the crust or contour of it: What is its length? Well if an entire circle is

and here the difficult bit:

radians is: (arc length)/(radius)

Your arc length, for half circle, we saw that was

Is it clear?...probably not...