In a parallelogram, the opposite sides of the shape are parallel. Also, the opposite angles have the same measure. This means that the angle opposite to your 45° is also 45°. Another rule of parallelograms states that consecutive angles (right next to each other) are supplementary. That means that if you add their measures together, you get 180°. Subtract 45° that we know from 180° to find the remaining angle. 180-45=135. This means the the other two angles are 135° and are opposite of each other. It would look something like this: ________________________ (45°) ----> / / <------- (135°) / / (135°) --> /__________________________/ <------ (45°)
