Geometry

Pythagorean Theorem

The Pythagorean Theorem states that in a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.

Meaning

What Is Pythagorean Theorem?

The Pythagorean Theorem states that in a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.

Examples

Examples of Pythagorean Theorem

13² + 4² = 5²
25² + 12² = 13²
38² + 15² = 17²
Understand

Formula and Key Points

Formula / rule
a² + b² = c²
  • It applies only to right-angled triangles.
  • The hypotenuse c is opposite the right angle.
  • It can be used to find a missing side length.
  • The converse can help test whether a triangle is right-angled.
CSE Connection

Why This Matters in Computer Science

Used in graphics, games, robotics, computer vision, spatial algorithms and coordinate calculations.

Step by Step

Worked Example

Problem

A right triangle has legs 6 and 8. Find the hypotenuse.

  1. Use a² + b² = c².
  2. Substitute: 6² + 8² = c².
  3. Calculate: 36 + 64 = 100.
  4. Take the square root: c = 10.
✓
Final Answer10
Try Your Own Problem in Math Solver →
Compare

Triangle Side Roles

SideMeaningExample value
aOne leg6
bOther leg8
cHypotenuse, opposite 90°10
FAQ

Pythagorean Theorem: Frequently Asked Questions

When can I use the Pythagorean Theorem?

Use it for right-angled triangles when you know two side lengths and need the third.

Which side is c?

c is the hypotenuse, the longest side opposite the right angle.