• Triangles B, C, D are multiples of triangle A
• This is called the {3, 4, 5} family
• There are infinite members of this family.

• Other common families that will help you by saving time
• {5, 12, 13}
• {7, 24, 25}
• (8, 15, 17}
• There are infinitely many more families but these are the most common

•
• Which family does this triangle belong to?
Look for the greatest common factor of both given sides.
•
GCF = 2, divide this out of both sides.
• This triangle belongs to {5, 12, 13}
• Missing side is 13(2) = 26

•
•
• Which family does this triangle belong to?
This is a {3, 4, 5} that has been divided by 2
So the missing side is
5
2

• Which family does this belong to?

• What family does this belong to?

• All of these can still be solved using the
Pythagorean Theorem if you do not recognize a family.
• The idea of families is to make your life easier not harder.