Question

Prove that the above quadrilateral (Fig 3.32) is a trapezium.

Answer 1

$KLMN$ is a qudrilateral

$\angle M={100}^o,\angle L={80}^o$

To show that $KLMN$ is a trapezium

$\angle M$ and $\angle N$ are same sided interior angles between $KL$ and $MN$

and $\angle M+\angle N={100}^o+{80}^o={180}^o$

We know that the sum of the same side interior angles of a trapezium is ${180}^o$

$\therefore KLMN$ is a trapezium