In a parallelogram, opposite angles are congruent. However, the same thing cannot be said for the other.
You can label one pair of opposite angles with x and the other 9x.
You also know that each quadrilateral has interior angles that add up to 360 so you can create the equation of
which can be simplified into
Now, you know the angle measures of one pair of opposite angles. to find the other you plug in 18 to our other equation and multiply 9 to get 162.
The angles of the parallelogram is 18,18, 162 and 162.
Note: you can check if this is right if all the angles add up to 360.