Question

Prove that ‘the sum of angles of a triangle is 180o’

Answer 1

Answer: In order to prove that the sum of angles of a triangle is 180, you must know the theorems of angles of a triangle. We know that, alternate interior angles are of equal magnitude. ... Now we have to substitute the angles. ∠PAB + ∠BAC + ∠CAQ = 180

Answer 2

Answer:

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 .......eq(i)

And, ∠3=∠5......eq(ii)

adding  eq(i)and(ii)

Therefore, ∠2+∠3=∠4+∠5

∠1+∠2+∠3=∠1+∠4+∠5  [adding∠1bothSide]

∠1+∠2+∠3=180  

 

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