Please help I have no clue how to do this

55°

Step-by-step explanation:

What we first have to know is the properties of a parallelogram.

1. The sum of the internal angles equals 360°

2. Oposite sides are parallel

3. Opposite angles are equal

Having this in mind, we can solve the problem.

If the opposite angles are equal, ir means that the angle opposite from A is 55° too, so following the order of the letters given (ABCD), the vertex C is opposite to vertex A, it means the angle C is 55°!

Hope you like it :)