Question

one angle of a triangle is 2 / 3 of a right angle . the greater of the other to exceed the lesser by 20 degree. Find the angles of the triangle in grades.

Answer 1

2/3 of a right triangle is 60 degrees.  Then x + (x+20) + 60 = 180 total.

2x + 80 = 180, so 2x = 100 and x = 50.  The angles are 50, 70 and 60 (degrees)

What do you mean by "grades?"