Question

2. If one angle of a triangle is equal to the sum of the other two, show that the
triangle is right angled triangle.
(Hint: Let angle A = angle B + angle C, Also angle A + angle B + angle C = 180º = angle A + angle A = 180°)​

Answer 1

let a triangle ABC those abc are angles

let angle a = angle b = z and angle c = y

let

angle a+ angle b= angle c

so

z+z= y( substituting the values)......,....,..equ1

we know that sum of angle of a triangle is 180 degrees

so,angle a+angle b+angle c= 180

implies; z+z+y=180(subtituting the values)

so

2y=180(from equ 1)

y= 90

Therefore,

angle c= 90

As

one angle of the triangle= 90 so,the triangle is right angled