Question

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

Answer 1

From figure, we observe that
$\angle M+\angle L={100}^{\circ }+{80}^{\circ }={180}^{\circ }$
So, the sum of interior angles on same side of a transversal ($ML$) is ${180}^{\circ }$
which is possible only if $NM$ and $KL$ are parallel.
Hence, $KLMN$ is a trapezium.