📐 Geometry Calculator

Right Triangle Calculator

Solve any right triangle from any two known values — sides a, b, c or angle A, B — using the Pythagorean theorem and trigonometric functions. Gives area, perimeter, and full angle set.

Enter Any Two Values

Leave the others blank — angle C is always 90°

Angle C = 90° always. Enter exactly 2 values.
Enter 2 values to solve the triangle
a² + b² = c² · Angle A + Angle B = 90°

Frequently Asked Questions

What is SOH-CAH-TOA?
SOH-CAH-TOA is a mnemonic for right triangle trig: Sin(A)=Opposite/Hypotenuse, Cos(A)=Adjacent/Hypotenuse, Tan(A)=Opposite/Adjacent. These formulas let you find any side or angle given one angle and one side.
What values do I need to provide?
Any 2 of the 5 values (a, b, c, A, B) are sufficient to solve the triangle — except the pair (A, B) since they always sum to 90°. The most common combinations are: two sides, or one side + one angle.