Add the lengths of all three sides
Use the formula: Perimeter = side 1 + side 2 + side 3
If one side is missing, find it first before adding
Make sure all side lengths are in the same unit
Write the final answer with the correct unit
Add the lengths of all three sides
Use the formula: Perimeter = side 1 + side 2 + side 3
If one side is missing, find it first before adding
Make sure all side lengths are in the same unit
Write the final answer with the correct unit