Explain how a square is a rhombus.

Explain how a square is a rectangle.

Name the quadrilaterals whose diagonals bisect each other.

Name the quadrilaterals whose diagonals are perpendicular bisectors of each other.

Name the quadrilaterals whose diagonals are equal.

In the given figure, $\mathrm{ABCD}$ is a rhombus, find the values of $x,y$ and $z$.

In the given figure, $ABCD$ is a trapezium. If $\angle A:\angle D=5:7, \angle B=(3x+11)°$ and $\angle C=(5x-31)°,$ then find all the angles of the trapezium.

In the given figure, $\mathrm{ABCD}$ is a rectangle. If $\angle \mathrm{CEB}:\angle \mathrm{ECB}=3:2$, if $\angle \mathrm{CEB}=k°$ then find $k$.