Question

prove that sum of three angles of a triangle equals to 180 degrees​

Answer 1

We know that a triangle has acute angles which are less than 90° . It can also be right angled triangle which has one right angle of 90°.It is the fixed property (angle sum property) which means that if we add all three angles of a triangle then it will be 180°. If one angle is 50° and other is 75° and we don't know the third angle . Then we will take the unknown angle as x and we add x+50+75=180 .

Then, x+ 125=180

X =180-125

X = 55°

Answer 2

Answer

According to the figure in attachment;

1 + 2 = 4 (exterior angle property)

4 = 180 - 3 (linear pair)

=> 1 + 2 = 180 - 3

=> 1 + 2 + 3 = 180

HENCE PROVED