Input Values

Result

Enter base and equal side length, then click Calculate.

About Isosceles Triangles

An isosceles triangle has two equal sides and two equal angles opposite those sides.

  • Height: h = √(s² - (b/2)²)
  • Area: A = (base × height) / 2
  • Perimeter: P = 2s + base

Where s is the length of equal sides and b is the base.

Plane Geometry Calculators