Answer: x=100
Explanation:
In parallelograms the opposite angles are equal. As the bottom left angle is 80° the opposite angle (top right), is also 80°. All 4 angles in a quadrilateral must add up to 360. Because you know 2 angles added together are 160° the other two angles must equal 200°. As opposite angles are equal you know 2x=200, divide by 2 x=100