Calculate triangle area from all three side lengths using Heron's formula. Check the triangle inequality and find the semiperimeter and area from three sides.
Heron's formula is useful when the perpendicular height is not known but all three sides can be measured or are given.
The semiperimeter is half the perimeter.
The three side lengths must satisfy a+b>c, a+c>b and b+c>a for a non-degenerate triangle.
| Side a | 5 cm |
| Side b | 6 cm |
| Side c | 7 cm |
| Triangle Area | 14.6969 |
| Semiperimeter | 9 |
| Valid Triangle | 1 |
The semiperimeter is 9 cm and the area is about 14.6969 square centimetres.
Try this example →It is a formula for finding triangle area from three side lengths using the semiperimeter.
No. Heron's formula calculates the area directly from the three sides.
No. The three triangle inequality conditions must be satisfied.
Using Heron's formula, the area is approximately 14.697 square units.