# NCERT Solutions for Class 7 Maths Chapter 6: The triangle and its properties

A triangle can be defined as a figure having three sides, three vertices and three angles. Sum of three interior angles of a triangle is 180 degrees. In Ex 6.1, students will learn about triangles, its types, its properties, and angles. Triangles have two classifications based on their sides and angles. Triangles based on sides are equilateral, scalene and isosceles triangle and triangles based on Acute, Obtuse, and right-angle angles. It contains a topic like medians of triangles and altitudes of triangles. In Ex 6.2 you will get to know about Exterior angle of a triangle, and it's property. The value of the exterior angle of a triangle is equal to the sum of opposite interior angles. In Ex 6.3, students will get to know about angle sum property. The property is associated with all the three angles of a triangle.

The sum of all three angles is 180. In Ex 6.4 two special triangle- equilateral and isosceles and the sum of lengths of two sides of a triangle is discussed. An equilateral triangle is a triangle in which all three sides are equal. An isosceles triangle is where two sides are equal so the angle might be 45 degrees. In Ex 6.5, students will get to know about a right-angled triangle and hypotenuse. The main topic of this chapter is

• Medians of a triangle
• Altitudes of a triangle
• Exterior angle of a triangle and its property
• Angle sum property of a triangle
• Two special triangle: Equilateral and Isosceles
• Sum of the side-lengths of two sides of a triangle
• Right-angled triangles and Pythagoras property