Triangle from 3 sides
Enter your numbers — the results update instantly.
Area14.7 cm²
Perimeter18 cm
Angle A44.42 °
Angle B57.12 °
Angle C78.46 °
Circumradius3.57 cm
Inradius1.63 cm
Worked example
Given: a = 5 cm; b = 6 cm; c = 7 cm
Result: Area = 14.7 cm²; Perimeter = 18 cm; Angle A = 44.42 °; Angle B = 57.12 °; Angle C = 78.46 °; Circumradius = 3.57 cm; Inradius = 1.63 cm
How it is calculated
1. Enter the values you know. 2. The calculator converts them to base units and applies the formula. 3. The result is shown in the unit you choose.
Frequently asked questions
How do I calculate it?
Given: a = 5 cm; b = 6 cm; c = 7 cm. Result: Area = 14.7 cm²; Perimeter = 18 cm; Angle A = 44.42 °; Angle B = 57.12 °; Angle C = 78.46 °; Circumradius = 3.57 cm; Inradius = 1.63 cm.
Is the calculator free and private?
Yes. It is free, needs no sign-up and runs in your browser — the numbers you type stay on your device.