Question

In triangle ,ABC angle A = x° , angle B =3x° , and angle C=y° if (3y-5x)=30 .Show that the triangle is right angled​

Answer 1

3x is going to be 90 and complete proving is in this page

Answer 2

sum of internal angles in a triangle=180°

so A+B+C=180°

x+3x+y=180°

4x+y=180°

y=180°-4x --------------->(1)

but given 3y-5x=30 ------------>(2)

so by keeping (1) in (2),

3*(180-4x)-5x=30

540-17x=30

17x=510

x=30, now y=180-4*30=60

so A=30°, B=90° ,C=60°

clearly it is a right - angled triangle