Question

If one angle of a triangle is equal to the sum of other two, show that the triangle is a right triangle.

Answer 1

let the angles be x y and z
x=y+z
x+y+z=180
put x =y+z
y+z+y+z=180
2(y+z)=180
y+z=90______(1)

x+y+z=180
put y+z=90
x+90=180
x=90
hence one angle is 90 therefore it is a right angled triangle