Answer:
C=84, D=80,b=99 and a=81
Step-by-step explanation:
In a quadrilateral, it's opposite measurements has to be equal to 180 degrees. So, for example if one side is 100 then the opposite side has to be equal to 80 so that if you add them there sum would be 180 degree.
Sorry, but I am not sure about a but you can try 81 degrees if you want. Hope this helps you!
