The value of x is 113 because the 3 angles in a triangle add up to 180° so 180 subtracted by 28° and 39° gives the value of angle x.
The value of y is 67° because x and y are supplementary angles which means they add up to 180°. So 180-113 gives y.
The value of z is 49° because if you subtract the 180° that makes up the triangle from 67 and 64, you get 49.
