Using the Right Triangle Calculator
Use matching units for both legs. The area will use the corresponding square unit, while the angles are reported in degrees. The angle opposite a longer leg will be larger.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Leg a
- 3
- Leg b
- 4
Example result
- Hypotenuse
- 5
- Area
- 6
- Angle A (degrees)
- 36.869898
- Angle B (degrees)
- 53.130102
Method and assumptions
c² = a² + b². Angles are obtained with the inverse tangent.
Match the measurements to the shape
Sketch the shape and label each input before calculating. A radius, diameter, perpendicular height and sloping edge can have similar-looking measurements while playing different roles in a formula. Use one consistent length unit. Area will then be in its square units and volume in its cubic units, rather than the original length unit.
Common question
Do the two reported angles add up to 90 degrees?
Yes, apart from display rounding. The third angle is already the triangle’s 90-degree right angle, and all three interior angles total 180 degrees.
Guide updated .