Divide the measure of all 3 angles into 10 parts...1 part is the measure of angle x, and the other angles add up to the other 9 parts. 180/10=18...so x = 18. So angle y and z together add up to the other 162 degrees. Divide 162 in half to find the “middle”...162/2=81. Since we were told that the difference between y and z is 20...y would be 10 less than that middle number, and z would be 10 more than it...so y=71, and z=91. The answers are... X=18, Y =71, Z=91
