Answer with explanation:
Theorem : The diagonal of a parallelogram divides it into two congruent triangles.
Properties of parallelogram
1. Opposite sides are equal and parallel.
2. Diagonal bisect each other.
3. Opposite Angles are equal.
If you will look at the first three options
A: Diagonals of a parallelogram bisect opposite angles.→→False(Alternate angles are equal)
B: Consecutive sides of a parallelogram are congruent.→→→False(Opposite sides are congruent)
C: Consecutive angles of a parallelogram are congruent.→→→False(Opposite angles are congruent)
D: Consecutive angles of a parallelogram are supplementary.→→→→True
For,any parallelogram, having vertices , A, B and C and D
Opposite sides are parallel, so
1.∠A + ∠B=180°
2.∠C + ∠B=180°
3.∠C+ ∠D=180°
4. ∠A + ∠D=180°
Option D