Right Triangle Calculator and Solver

Five easy to use calculators to solve right triangle problems depending on which information you are given. The figure shown below will be used for sides and angle notations.

right triangle used for notation

In the above right triangle the sides that make and angle of 90° are a and b, and h is the hypotenuse.
These calculators may be used to check your answers to questions that you have solved analytically.


Formulas Used in the Different Calculators

The Pythagorean theorem used in the above triangle gives

a2 + b2 = h2

a = √ (h2 - b2)

b = √ (h2 - a2)


The trigonometric ratios used to find angles A and B are given by

sin(A) = a / h ,     A = arctan(a / h)

sin(B) = b / h ,    B = arctan(b / h)


The area and perimeter of the right triangle are given by

Area = (1/2) a b

Perimeter = a + b + h



Calculator 1 - You know one side and the hypotenuse

How to use the calculators

Enter the side and the hypotenuse as positive real numbers and press "calculate".

side a = hypotenuse h =
side b =
angle A = degrees
angle B = degrees
angle C = degrees
area =
perimeter =

Calculator 2 - You know the two sides of the right triangle

How to use the calculators

Enter the two sides as positive real numbers and press "calculate".

side a = side b =
hypotenuse h =
angle A = degrees
angle B = degrees
angle C = degrees
area =
perimeter =

Calculator 3 - You know one side and the angle opposite to it

How to use the calculators

Enter the side and the opposite angle as positive real numbers and press "calculate".

side a = angle A =
hypotenuse h =
side b =
angle B = degrees
angle C = degrees
area =
perimeter =

Calculator 4 - You know the hypotenuse and one angle

How to use the calculators

Enter the hypotenuse and the angle as positive real numbers and press "calculate".

hypotenuse h = angle A =
side a =
side b =
angle B = degrees
angle C = degrees
area =
perimeter =

Calculator 5 - You know the perimeter and area of a right triangle

How to use the calculators
You might have to review area and perimeter of right triangles in order to understand the formulas used in this calculator.
Enter the perimeter and the area as positive real numbers and press "calculate".

perimeter p = area a =
side a =
side b =
hypotenuse h =
angle A = degrees
angle B = degrees
angle C = degrees

More References and Links

Solve Right Triangle Problems
area and perimeter of right triangles
Online Geometry Calculators and Solvers.