Question

state and prove angle sum property of a triangle​

Answer 1

Answer:

state : sum of the all angle of the triangle is 180

Diagram : AB ||CD and APB is a straight line

construction: let AB || CD

To prove: angle 1+4+5= 180

proof: since AB is straight line( sum angle is 180)

so, Angle 1+angle 2+angle 3= 180

and now given that AB. ||CD. ( from construction)

then angle 2=angle 5 ( Alternate interior angle)

angle 3=angle 4 ( Alternate interior angle)

so there fore. 1+4+5= 180

hence proved