Right Triangle Calculator
Hypotenuse, angles, area and perimeter from two legs.
How it works
c = √(a² + b²); A = atan(a/b); Area = a×b÷2
Angle A is opposite side a; angles A and B are complementary (sum to 90°).
FAQ
Can I use hypotenuse and one leg?
Yes: other leg = √(c² − a²).
Worked example
Legs 3 and 4, hypotenuse 5.
Angle A opposite 3: tan A = 3/4, A = arctan(0.75) ≈ 36.87°; the other acute angle is 53.13°.
Notes and limitations
Angles sum to 180°, so the two acute angles are complementary. When using tan, be sure which side is opposite and which is adjacent; arctan returns −90° to 90°.