**Question:**

Diagonals of a quadrilateral ABCD bisect each other. If ∠A= 35°, determine ∠B.

**Solution:**

Since, diagonals of a quadrilateral bisect each other, so it is a parallelogram.

Therefore, the sum of interior angles between two parallel lines is 180° i.e.,

∠A+∠B = 180°

=> ∠B = 180° – ∠A = 180°- 35°

[∴ ∠A = 35°, given]

=> ∠B = 145°