Answer:
45°
Step-by-step explanation:
A parallelogram is a polygon with 4 sides and 4 angles (that is a quadrilateral).
For a parallelogram ABCD, Opposite sides and opposite angles are equal (i.e. BC = AD and ∠A = ∠C).
Consecutive angles are supplementary that is ∠A + ∠B = 180°.
The diagonals of a parallelogram bisect each other also separating the parallelogram into two congruent triangles.
In parallelogram HIJK, ∠H and ∠J are opposite angles. hence:
∠H = ∠J (opposite angles of a parallelogram are equal)
∠J = 45°