Question

explain the theorem 6.7 the sum of the angles of a triangle is 180°​

Answer 1

Step-by-step explanation:

Given: AΔABC

To prove: ∠1+∠2+∠3=180°

Construction: through A, draw a line XY||BC.

Proof: Since 1||BC

therefore,

∠2=∠4---------(1)

∠3=∠5---------(2)

adding equation (1) and (2)

therefore,

∠2+∠3=∠4+∠5

Adding ∠1 both sides

∠1+∠2+∠3=∠1+∠4+∠5

∠1+∠2+∠3=180°

Thus,

The sum of three angles of a triangle is 180°

Answer 2

Step-by-step explanation:

hope it helps you.......................