Let ABCD be parallelogram.
Given that sum of two opposite angles of a parallelogram is 130o
Given ∠B + ∠D = 130o
∠B + ∠B = 130o [since opposite angles of a parallelogram are equal]
2∠B = 130o
∠B= 130/2 = 65o
Therefore ∠D = 65o
Also ∠B + ∠C = 180o [Since ∠B and ∠C are adjacent angles]
65o+ ∠C = 180o
∠C = 180o– 65o= 115o
∠A = ∠C = 115o [since opposite angles of a parallelogram are equal]