Question

prove that the sum of the angles of a triangle is 180°​

Answer 1

angle sum of property of triangle states that the sum of a triangle is 180

prove the above poverty of triangle

u have to draw a line /overleftrightarrow ( pq)

parallel to the side bc of the given triangle

Answer 2

Given,

• A tringle ABC

To prove,

• ∠A+∠B+∠C = 180° ==> ∠1 + ∠2 + ∠3 = 180°

construction,

• Through A, draw a line l parallel to BC.

Proof,

since 1 || bc Therefore,

• ∠2 = ∠4 ••••••••equation (i)
• And, ∠3=∠5••••••equation (ii)

adding equation (i) and (ii)

1. ∠2 + ∠3 = ∠4 + ∠5
2. ∠1 + ∠2 + ∠3 = ∠1 + ∠4 + ∠5

[ adding ∠1 both Side]

• ∠1+∠2+∠3=180°

Thus, the sum of three angles of a triangle is 180°.

$\huge\colorbox{red}{Hence proved ✔️}$