Enter the side length of the equilateral triangle. The calculator then derives every standard property from that one value.

1. Enter a positive side length.
2. Read the area, height, perimeter, and circle radii.
3. Use the formulas section to verify the derivation.

For side 6, the area is 15.588457 and the height is 5.196152.

The circumradius is 3.464102 and the inradius is 1.732051.

Zero and negative side lengths are rejected before any square root is taken.

The geometry here is exact, so no hidden mode switching or special-case inputs are needed.