Triangle Dimensions

Geometry Analysis

Hypotenuse (Side c)
5.00
Total Area
6.00
Perimeter
12.00
Internal Angles (A / B)
36.9° / 53.1°

A Right Triangle Calculator is a foundational geometry tool used heavily in mathematics, architecture, engineering, and construction. A right triangle is defined as any triangle that contains exactly one 90-degree angle. By knowing the lengths of the two straight legs, you can easily calculate the longest side, the area, and the inner angles.

How to Calculate the Hypotenuse

The longest side of a right triangle, situated directly opposite the 90-degree angle, is called the hypotenuse. You can find its exact length using the famous Pythagorean theorem, which states that the square of the hypotenuse is equal to the sum of the squares of the other two sides.

Formula: a² + b² = c²

For example, if the base (Side a) is 3 units long and the height (Side b) is 4 units long, you square them to get 9 and 16. Adding those together gives 25. The square root of 25 is 5, meaning your hypotenuse (Side c) is exactly 5 units long.

How to Use This Geometry Tool

  • Enter the length of the base into the Side a input box.
  • Enter the length of the vertical height into the Side b input box.
  • The calculator instantly updates to display the Hypotenuse on the main dashboard.
  • Review the additional geometric metrics, including the total enclosed Area, the outer Perimeter, and the precise measurements of the two non-right angles.

Frequently Asked Questions

How is the Area of a right triangle calculated?

The area is calculated by multiplying the base by the height, and then dividing that result by two. The formula is Area = 0.5 × a × b. Because a right triangle is essentially half of a rectangle, you are calculating the area of that rectangle and cutting it in half.

What are Angles A and B?

Every triangle contains a total of 180 degrees. Since a right triangle always has one 90-degree angle, the remaining two angles (Angle A and Angle B) must always add up to exactly 90 degrees. These are calculated using inverse trigonometric functions based on the lengths of your inputted sides.

What makes a right triangle isosceles?

An isosceles right triangle occurs when the base (Side a) and the height (Side b) are exactly the same length. When this happens, both Angle A and Angle B will be exactly 45 degrees, creating perfect symmetry along the diagonal.