13. <YOU is supplementary to <XOY so the two of those angle measures added together will equal 180 degrees. It is given that <XOY is 144 degrees. To get the value of <YOU, you subtract 144 from 180. 180-144 is 36. m<YOU =36
14. <XOY and <WOU are vertical angles which means that their angle measures are the same. Given that <XOY is 144 degrees, <WOU is also 144 degrees. <WOV is 80 degrees, so you subtract that amount from the measure of <WOU to get the angle measure of UOV. 144 - 80=64. m<UOV=64
