Question

the sum of the angles of a triangle is equal to the third sides. find the measures of a third angle.

Answer 1

Let the three sides be

a,b and c.

Given a=b

We know that sum of the angles of a triangle is 180°

This means

a+b+c = 180°

But b=a

Thus,

a+a+c = 180°

2a +c = 180°........Eq[1]


Also given,

2a=c.....Eq[2]

Put Eq[2] in Eq[1]

We get,

2a+2a = 180°

4a=180°

a=45°..
b=45°
c=2a=2×45°
thus c=90°.

Thanks