Use our Equilateral Triangle Calculator to find the side length, area, perimeter, height, or angle from any one known value, complete with step-by-step solutions.

Use our 45-45-90 Triangle Calculator to find the legs, hypotenuse, altitude (height), area, or perimeter from any one known value, complete with step-by-step solutions.

Use our 30 60 90 Triangle Calculator to find the short leg, long leg, hypotenuse, altitude (height), area, or perimeter from any one known value, with step-by-step solutions.

Use our Pythagorean Theorem Calculator to solve right-angled triangle problems—find sides, angles, triangle height, area, or perimeter with step-by-step solutions.