Question

Prove that sum of interior angles of a triangle is 180°.​

Answer 1

GIVEN : A triangle ABC

TO PROVE: <A + <B + <C +<D =180°

CONSTRUCTION: Draw a line l parallel to BC.

PROOF: since l parallel to BC

Therefore,

<2=<4 [ alternate interior angles]

<3=<5 [ alternate interior angles]

Now,

<2+<3=<4+<5

Adding <1 on both sides

=><1+<2<3=<1+<4+<5

sum of angles at point on line is 180°

=> <1+<2+<3=180°

Answer 2

Answer:

:- it's pagal

hope it helps