Question

The sum of two angle of triangle is equal to third angle determine the third angle

Answer 1

third angle is known as exterior angle of the triangle

Answer 2

Let the first and second angle be a a and b. then ,

Third angle = a+b


By angle sum property of triangle

a +b + a+b = 180

=> 2a +2b = 180

=> 2(a+b) = 180

=> a+b = 90°

Third angle = 90°