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

Video Examples: Triangles

Examples of Triangle

Solved Example on Triangle

Ques: 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 to 5 m.
Step 2: Since two sides are equal, the land is in the form of an isosceles triangle.