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