Right Triangle Calculators

Right Triangle Calculators is a free website for students, teachers and tradespeople. Enter any two known values of a right triangle and it finds the rest: sides, angles, area, perimeter, altitude, inradius and circumradius. Every result shows the step-by-step working and a to-scale diagram, so you can see why the answer is right. There are separate calculators for the hypotenuse, the Pythagorean theorem and the 30-60-90 and 45-45-90 triangles, plus a formula reference. Everything runs in your browser, in 8 languages, with no sign-up.