In the drawing, what is the measurment of angle y?

According to the vertical angle rule we know that x is 40 degrees. The sum of all angles in a triangle make 180, so the sum of x, 60, and the third angle is 180. x is 40 so the third angle is 180-60-40 which is 80 degrees.  y is an adjacent angle, which means that the sum of y and 80 degrees is 180. 180-80 is 100, so y is 100 degrees.