#### Param Publication

Angle Sum Property of a Triangle:
The sum of the measures of three angles of a triangle is 180°.

Proof of Angle Sum Property of a Triangle

Given : A triangle ABC.
To prove :  ∠ A +∠B +∠C = 180°
Construction : Draw a line segment PQ through A and parallel to BC.

Proof:    Mark the angles as indicated in the figure.

Hence, ∠ A +∠B +∠C = 180°
or sum of the angles of a triangle is 180°

ANGLE BISECTORS OF A TRIANGLE AND IN-CENTRE
Angle Bisectors :-

Angle bisector of a triangle is a line segment which bisect the angle and whose end points lies on the vertex and its opposite side.
•    In the given figure, AD is the bisector of
Incentre

•    In-centre is the meeting point of all three angle bisectors of a triangle.
•    In the given figure, I is the Incentre of
•    In-centre always lies inside the triangle.
•    The perpendicular distance from incentre to the side of triangle is always same.
IP = IQ = IR
•    A circle can be drawn inside the triangle by assuming I as centre and IP as radius.

PERPENDICULAR BISECTOR AND CIRCUMCENTRE
Perpendicular Bisector

It is a line segment which is perpendicular to the side of a triangle and passing through the mid point of the side.
In the given figure MN is the perpendicular bisector for

#### LIVE MATHS FOR CLASS 7

###### EDUCARE

Course : CBSE Class 7

Start Date : 18.01.2022

End Date : 03.03.2022

Types of Batch : Live Online Class

 Subject M T W T F S S Mathematics(120 hours) 7:00 PM 7:00 PM 7:00 PM 7:00 PM 7:00 PM - -