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Sides and angles of a right triangle.
The Right Triangle Calculator takes the two legs of a right-angled triangle and computes everything else: the hypotenuse, the area, the perimeter and both acute angles.
It combines the Pythagorean theorem with basic trigonometry, making it useful for construction, ramps, roof pitches and any layout that relies on a right angle.
The two acute angles always add up to 90°, because the third angle is the right angle.
Multiply the two legs and halve the result: Area = ½ × a × b, since the legs act as base and height.
Angle A = arctan(a ÷ b) in degrees, and angle B = 90° − A. Together the two acute angles make 90°.
The side opposite the right angle — the longest side — found with c = √(a² + b²).
A triangle's angles total 180°. With one angle fixed at 90°, the remaining two must sum to 90°.