• A three-sided polygon is called a triangle. In simple words, a triangle is a polygon with three sides.

More about Triangle

• Equilateral Triangle: A triangle with all sides of the same length is called an equilateral triangle.
• Isosceles Triangle: A triangle with at least two sides of the same length is called an isosceles triangle.
• Scalene Triangle: A triangle with no sides of the same length is called a scalene triangle.
• Right Triangle: A triangle with one right angle is called a right triangle.
• Acute Triangle: A triangle with all its angles less than 90° is called an acute triangle.
• Obtuse Triangle: A triangle with one of its angle measuring more than 90° is called an obtuse triangle.

Examples of Triangle

Solved Example on Triangle

A piece of land is in the shape of a triangle with the sides of length 5 m, 5 m, and 3 m? What is this triangle called?   
Choices:
A. right triangle
B. scalene triangle
C. isosceles triangle
D. equilateral triangle
Correct Answer: C
Solution:
Step 1: Two of the three sides are equal (5 m, 5 m).                             
Step 2: So, the triangle is an isosceles triangle.

Related Terms for Triangle

• Polygon
• Three-sided figure