If ABCD is a parallelogram, then which of the following is true?
∠A=130∘,∠C=130∘,∠B=50∘
In a parallelogram, the adjacent sides and angles are not equal and no sides are perpendicular to other.
∠A+∠B=130∘+50∘=180∘
Here, ∠A and ∠B are co-interior angles and their sum is 180∘.
By the converse of co-interior angles theorem, AD || BC and AB is the transversal.
∠D+∠A=50∘+130∘=180∘
Here, ∠D and ∠A are co-interior angles and their sum is 180∘.
By the converse of co-interior angles theorem, AB || DC and AD is the transversal.