Calculate the area, height, perimeter, inradius and circumradius of an equilateral triangle from its side length.
Fill in the details and click Calculate to see your results.
All three sides of an equilateral triangle are equal and each interior angle is 60 degrees.
The altitude divides an equilateral triangle into two 30-60-90 triangles.
The calculator provides several standard properties from the single side length.
| Side Length | 10 cm |
| Triangle Area | 43.3013 |
| Height | 8.66025 |
| Perimeter | 30 |
| Inradius | 2.88675 |
| Circumradius | 5.7735 |
The area is about 43.3013 square centimetres and the height is about 8.66025 cm.
Try this example →Area equals √3 times side squared divided by 4.
All three angles are 60 degrees.
Yes. Height equals √3 times the side divided by 2.
The area becomes four times as large because area depends on the square of the side.