Isosceles triangle

What is an Isosceles Triangle?

An isosceles triangle is a special kind of triangle. It has two sides that are the same length. The two angles next to these sides are also the same size. You can find isosceles triangles in many places, like in buildings and nature.

The two equal sides are called legs. The third side is called the base. If you draw a line from the middle of the base to the top point, the triangle splits into two matching halves. This is called reflection symmetry.

Where Do We See Them?

Isosceles triangles have been studied for thousands of years. People in ancient Egyptian mathematics and Babylonian mathematics knew about them. Today, we see them in architecture. For example, the tops of buildings called pediments and the shapes of roofs called gables often use isosceles triangles because they look balanced and nice.

Fun Facts

Did you know that equilateral triangles are a special type of isosceles triangle? This is because all three sides are equal, which means at least two sides are equal too. Isosceles triangles are also used in mathematics to help solve problems with moving objects, like planets.

Isosceles triangles are everywhere once you start looking for them!