# How Do You Find Perimeter Of Semi Circle?

“So how do find the perimeter or circumference of a semi circle? Hi, I’m, Jimmy and we’re here to explore that right now. Well, if you know how to find the perimeter or circumference of a circle, then you’ll know how to find the perimeter or circumference of a semi circle. You may have noticed I use the word perimeter and circumference in the same context, because in circle terms, they are one in the same. But circumference is used more widely in math. So, it all starts with the circumference of a circle which is C equals two pi r. Now, a semi circle by definition is that of a half circle. So, if a semi circle is a half circle, then the circumference of a semi circle, you just take the formula, two pi r, and divide that by two. Or multiply by half. And what ends up happening, is that the twos will cancel, so you’re left with pi r. So the formula for the circumference of a semi circle is pi times r which is the radius of the original circle. So let’s just say you are given that the radi