Squares on a Triangle

In the picture

1. 1A small square in the triangle’s corner: the corner is a right angle.
2. 2A blue square on the short side: its area is 3 × 3.
3. 3A yellow square on the other short side: its area is 4 × 4.
4. 4A green square on the longest side: its area is 5 × 5.

Examples

• Checking a corner with a carpenter’s square.
• A ladder leaning against a wall can be checked with the 3-4-5 rule.

Quiz: Squares on a Triangle (Age 13)

1. 1

   In a right triangle, what does the square on the longest side equal?

   • The difference between the squares on the two shorter sides
   • The product of the two shorter sides
   • The sum of the squares on the two shorter sides
2. 2

   Which triangles follow the rule that the square on the longest side equals the sum of the squares on the other two sides?

   • Only right triangles
   • All triangles
   • Only triangles with sides 3, 4, and 5
3. 3

   In the 3-4-5 example, what is the area of the square on the longest side?

   • 12
   • 7
   • 25

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.