Class 7 Maths The Triangle and its Properties Introduction


A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry.  It has three vertices, three sides and three angles. A triangle with vertices A, B, and C is denoted by ∆ ABC.


Let us consider a triangle ABC.

Three sides are: AB, BC and CA

Three vertices are: A, B and C

Three angles are: ∠ABC, ∠BAC, ∠BCA

The side opposite to vertex A is BC. The side opposite to vertex B is AC. The side opposite to vertex C is AB. We can classify triangles based on sides and angles.

(i) Based on Sides: Scalene, Isosceles and Equilateral triangles.

(ii) Based on Angles: Acute-angled, Obtuse-angled and Right-angled triangles.

Share these Notes with your friends  

< Prev Next >

You can check our 5-step learning process