Perimeter 2

Adding it all together

Perimeter is all about the distance around the outside of our shape, so the perimeter of a triangle means adding $3$3 sides together. We can calculate the perimeter of equilateral, isosceles and scalene triangles, using what we know about those triangles, to help with missing values.

Let's see what features each of those triangles has, and how it can help us work out the perimeter of the triangle.

 

Worked Example

Question 1

 

The power of the perimeter

This is where the perimeter helps us! If we know the perimeter of our triangle, we can work out how long one, or more, of the sides are. In fact, if we know the perimeter of an equilateral triangle, we can work out how long every side is. Let's look at using what we know to find missing values.

 

Worked Examples

Question 2

Question 3