Question

The sum of the angle of triangle is 180°​

Answer 1

Answer:

In a Euclidean space, the sum of angles of a triangle equals the straight angle (180 degrees, π radians, two right angles, or a half-turn). A triangle has three angles, one at each vertex, bounded by a pair of adjacent sides.

Answer 2

Answer:

A triangle ABC.

To prove :

∠A+∠B+∠C=180  

o

⟹∠1+∠2+∠3=180  

o

 

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  

o

 

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