10.Explain how this figure is a trapezium. Which of its two sides are parallel?

We have, \(∠M + ∠L = 100^{\circ} + 80^{\circ} = 180^{\circ}\)
∠M and ∠L are the adjacent angles, and sum of adjacent interior angles is \(180^{\circ}\) and also KL is parallel to NM.Hence KLMN is a trapezium.