Question

်
prove that the sum of
of triangle
is 180​

Answer 1

Answer:

this is simple theorem as you see in book if any doubt in step then sent i will explain

Answer 2

Step-by-step explanation:

Given :

A triangle ABC.

To prove :

∠A+∠B+∠C=180°

⟹∠1+∠2+∠3=180°

Construction :

Through A, draw a line l parallel to BC.

Proof :

Since l ║BC. Therefore,

∠2=∠4 ....... (i)

And, ∠3=∠5..... (ii)

adding (i) and (ii)

Therefore, ∠2+∠3=∠4+∠5

∠1+∠2+∠3=∠1+∠4+∠5  [adding ∠1 to both Sides]

∠1+∠2+∠3=180°

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