# Isosceles Trapezoid Formula

As a quadrilateral, the trapezoid is a four-sided shape. The unique property about the trapezoid is that it has only one pair of parallel sides. Isosceles trapezoid is a type of trapezoid where the non-parallel sides are equal in length.

**There are two isosceles trapezoid formulas**

The Perimeter of isosceles trapezoid formula is

\[\large Perimeter\;of\;Isosceles\;Trapeziod=a+b+2c\]

Where,

a, b and c are the sides of the trapezoid

The Area of isosceles trapezoid formula is

\[\large Area\;of\;Isosceles\;Trapeziod=h\left [\frac{a+b}{2}\right]\]

Where,

a and b are the parallel sides of trapezoid.

Solved Examples

**Question 1: **A trapezoid has legs 8 cm each in length. Its bases are 10 cm and 15 cm respectively. Calculate its perimeter.

**Solution:**

Given:

a = 10 cm

b = 15 cm

c = 8 cm

Perimeter is given by: p = a + b + 2c

= 10 + 15 + 2 $\times$ 8

= 41 cm.