### Video Transcript

What is the perimeter of this triangle?

The perimeter of a shape is the sum of all of its sides. A triangle has three sides. So we need to add together the lengths of each side. The first side is seven centimeters in length. And we add the second side, which is eight centimeters, and the third side, which is nine centimeters.

To find the perimeter, we need to add seven centimeters and eight centimeters and nine centimeters. So let’s add seven and eight. And that will give us 15. And then we add the nine centimeters. 15 plus nine is 24. The perimeter of this triangle is 24 centimeters. We found the perimeter by adding together the three sides.