Hypotenuse Calculator

Calculate the hypotenuse of a right triangle using multiple methods

Calculate Hypotenuse

Vertical leg length

Horizontal leg length

Ladder Safety Example

Problem

A ladder needs to reach a 10 ft high roof. For safety, the ladder should be placed at a 75.5° angle with the ground. How long should the ladder be?

Solution

Given: Height (side a) = 10 ft, Angle α = 75.5°

Formula: c = a / sin(α)

Calculation: c = 10 / sin(75.5°) = 10 / 0.9703 = 10.31 ft

Result: The ladder should be approximately 10.31 feet long

Safety tip: Follow the 4:1 rule - for every 4 feet of height, place the ladder base 1 foot from the wall

Hypotenuse Formulas

Two Sides

c = √(a² + b²)

Pythagorean theorem

Angle + Side

c = a / sin(α)
c = b / cos(α)

Trigonometric ratios

Area + Side

c = √(a² + (2×Area/a)²)

Using area formula

Quick Facts

The hypotenuse is always the longest side in a right triangle
It's the side opposite to the 90° angle
Common in construction, navigation, and physics
The word comes from Greek meaning "stretching under"

Understanding the Hypotenuse

What is a Hypotenuse?

The hypotenuse is the longest side of a right triangle. It's the side opposite to the right angle (90°). The term comes from the ancient Greek word "hypoteinousa," meaning "stretching under a right angle."

Key Properties

  • Always the longest side in a right triangle
  • Opposite to the 90° angle
  • Length given by the Pythagorean theorem
  • Essential for trigonometric calculations

Calculation Methods

Pythagorean Theorem

Most common method when both legs are known

c² = a² + b²

Take the square root to find c

Trigonometric Ratios

When you know an angle and one side

sin(θ) = opposite/hypotenuse

cos(θ) = adjacent/hypotenuse

Real-World Applications

Construction

Ladder placement, roof angles, structural supports

Navigation

Distance calculations, GPS systems, surveying

Physics

Vector calculations, force resolution, projectile motion