Let ∠A = x°, ∠B = \(\frac{2x^\circ}{3}\)
Since the sum of any two adjacent angles of a parallelogram is 180°,
∠A + ∠B = 180°
x° + \(\frac{2x^\circ}{3}\) = 180°
\(\frac{5x^\circ}{3}\) = 180°
\(5x^\circ\) = 540°
x° = 108°
∠A = 108°
∠B = 72°
Also, ∠B + ∠C = 180° [Since, ∠B and ∠C are adjacent angles]
72° + ∠C = 180°
∠C = (180° - 72°) = 108°
Further, ∠C + ∠D = 180° [Since, ∠C and ∠D are adjacent angles]
108° + ∠D = 180°
∠D = (180° - 108°) = 72°
Therefore, smallest angle of the parallelogram is 72°.
