Introduction

Isosceles triangle gets its name from the Greek terms iso, which means same, and Skelos, which means legs. The total space or region covered between the sides of an isosceles triangle in two-dimensional space is the area of an isosceles triangle. The definition of an isosceles triangle is a triangle with two equal sides, which also means two equal angles.

Isosceles Triangle Properties

An isosceles triangle has a few properties that set it apart from other triangles:

  • The legs are the 2 equal sides of an isosceles triangle, & the angle between them is known as the vertex angle or apex angle.
  • The other side of the vertex angle is the base angle, and base angles are equal.
  • The base and the vertex angle are bisected by the perpendicular from the vertex angle.
  • The vertex angle is the angle formed by two equal sides or any angle other than base angles.
  • The vertex angle of a right-angled isosceles triangle is 900, and the base angles are 450.

How to find area for isosceles triangle

 Height of an isosceles triangle can be computed if the lengths of the equal sides and the base are known. The formula for calculating the area of an Isosceles triangle based on its sides is as follows:

where,

 

b = the isosceles triangle’s base

h is the isosceles triangle’s height.

a = the sum of the lengths of the two equal sides

Area of isosceles triangle using Heron’s formula

When the lengths of all three sides are known, Heron’s formula is used to compute the area of a triangle. Using Heron’s formula, the area of the isosceles triangle is calculated as follows:

Conclusion

A triangle with (at least) two equal side lengths is called an isosceles triangle. The triangle is also equilateral if all three side lengths are equal. Isosceles triangles can in handy when trying to figure out unknown angles. Isosceles triangles have been applied as decorative elements in architecture and design from ancient times and can be found in pediments and gables of structures. The legs are the two equal sides of the triangle, and the base is the third side.