PEAZIT Aha card
Go straight to resources ↓Pythagoras: find the right angle first
In a right triangle, the square on the hypotenuse has the combined area of the squares on the legs.
| Side | Length | Square area |
|---|---|---|
| Leg a | 3 | 9 |
| Leg b | 4 | 16 |
| Hypotenuse c | 5 | 25 = 9 + 16 |
One worked example
- c² = 3² + 4² = 25Add square areas, not the lengths themselves.
- c = √25 = 5Take the positive square root to find the length.
Watch out: This form applies to right triangles. The hypotenuse must be opposite the right angle.
Goal, prerequisites and card origin
What you will learn: Calculate the hypotenuse of a right triangle.
What you need first: Right angles, squares and square roots.
An original PEAZIT working card. Independent expert review and effectiveness testing have not yet taken place. · v1
Show connections
In a right triangle, the square on the hypotenuse has the combined area of the squares on the legs.