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SAI International School

CLASS – VII

Mathematics

Chapter-6: Triangle and its properties-3
Lesson Notes - 3

SUBTOPICS:

 Two special triangles: Equilateral and isosceles,
 Sum of the lengths of two sides of a triangle

Equilateral triangle:

 A triangle in which all the three sides are of equal lengths.
 Each angle equals to 60 .
∘

Isosceles triangle:

 A triangle in which two sides are of equal lengths.
 Base angles opposite to the equal sides are equal