In the given figure, ABCD is a parallelogram, M is the mid-point of BD and BD bisects ∠B as well as ∠D. Then, ∠AMB = ?
Since, ABCD is a parallelogram,
∴∠B = ∠D (opposite angle)
1/2 ∠B = 1/2 ∠D
∠ADB = ∠ABD
∴ ADB is an isosceles triangle.
Since, M is the midpoint of BD
∴ AM is a median of ΔADB.
Now, ∠AMB = 90° (AM is perpendicular to BD)
∴Option C is correct