why all struggling like that.answer is d.bec they havent given the measures of triangle as a right angle.how all assume pythogeran theorem?the measures of right triangle are 3,4,5/3x,4x.5x/x,x,xroot 2/6,8,10/12,13,5.so the given is not right triangle.so we cant tell the angles.but we can tell that z>y>x.but cant tell that whether x+y is grater than 90 r not.so answer is d.