Explanation
A right triangle is a triangle that has one angle equal to 90°.
In a right triangle, there is a special relationship between the three sides called the Pythagorean formula.
This formula allows us to find a missing side when we know the other two sides.
Formula / Rule
In any right triangle:
c² = a² + b²
Where:
◉ c is the hypotenuse (the longest side, opposite the 90° angle)
◉ a and b are the other two sides (called the legs)
Example
Find the hypotenuse x when the sides are 3 and 4.
Step 1:
x² = 3² + 4²
Step 2:
x² = 9 + 16 = 25
Step 3:
x = 5
✅ So the hypotenuse is 5
Practice
Continue Learning
- Pythagorean Formula
- Pythagoras Theorem (a² + b² = c²) – Visual Proof 1
- Pythagoras Theorem (a² + b² = c²) – Visual Proof 2
- Pythagorean Theorem (Example)