The first category is based upon

**measurement of angles**. These triangles are Right triangle, Acute triangle, and Obtuse triangle.

The second category includes the triangles based on the

**measurements of their sides**. These triangles are called Equilateral triangle, Isosceles triangle, and Scalene triangle. Here is a description of each of the triangles:

**Right Triangle:**One angle of exactly 90 degrees.

**Acute Triangle:**All three angles are less than 90 degrees.

**Obtuse Triangle:**Only one angle is more than 90 degrees.

**Equilateral Triangle:**All of the sides are of equal measurement.

**Isosceles Triangle:**Two of the sides are the same in measurement.

**Scalene Triangle:**All of the sides are of different measurement.

Types of Triangles -7th Grade Math