Question 274830
If they are on the same side then angles A and B are supplementary (their sum is 180).

So we have:

1.) A + B = 180 and
2.) B = A + 30

Substituting A + 30 for B in equation 1.) gives us:

A + (A + 30) = 180

2*A = 150
A = 75
B = 105

If D is opposite A then D = 75 (opposite angles in a parallelogram are equal).

I'm not sure how your parallelogram is labeled. Sorry.