### Video Transcript

Given that the mean of the side lengths of a triangle is 150 centimeters, determine its perimeter.

We recall that the mean is a measure of centrality or average. It is the sum of all the values divided by the number of values. In this question, we are told that the mean is 150 centimeters. We know that a triangle has three sides. Therefore, the number of values is three.

The perimeter of a shape is the distance around the outside. It is the sum of all the side lengths. In this question, the sum of all the values is equal to 150 centimeters multiplied by three. This is equal to 450 centimeters. We can therefore conclude that the perimeter of the triangle is 450 centimeters.