I am not sure what is acute angles but if they are the other two angles of the rightangled triangle, then it would be easy to solve.firstly, a triangle has a total of 180 degrees so,180 dregree  90 degree = 90 degree( right angle = 90 degree)x + ( 3x  10) = 90 degreee.therefore x + 3x  10 = 90 degreeadd up x :4x  10 = 90plus 10 on both sides :4x  10 + 10 = 90 + 104x = 100x = 25hope i am correct
