If angles $A, B, C$ and $D$ of the quadrilateral $ABCD$,taken in order,are in the ratio $3:7:6:4$,then $ABCD$ is a

$ABCD$ is a trapezium in which $AB \parallel DC$ and $\angle A = \angle B = 45^{\circ}$. Find angles $C$ and $D$ of the trapezium.

$D$ and $E$ are the mid-points of the sides $AB$ and $AC$ of $\Delta ABC$ and $O$ is any point on side $BC$. $O$ is joined to $A$. If $P$ and $Q$ are the mid-points of $OB$ and $OC$ respectively,then $DEQP$ is

In $\Delta PQR$,$X, Y$ and $Z$ are the midpoints of $PQ, QR$ and $RP$ respectively. If $PQ = 7.2 \, cm$,$PR = 8.4 \, cm$ and $XZ = 3.8 \, cm$,then find the perimeter of $\Delta PQR$ and $\Delta XYZ$.

$E$ is the mid-point of the side $AD$ of the trapezium $ABCD$ with $AB \parallel DC$. $A$ line through $E$ drawn parallel to $AB$ intersects $BC$ at $F$. Show that $F$ is the mid-point of $BC$.

In $\Delta XYZ$,$A, B$ and $C$ are the midpoints of $XY, YZ$ and $XZ$ respectively. If $AB = 5.2\, cm$,$BC = 4.3\, cm$ and $AC = 6.5\, cm$,then find the perimeter of $\Delta XYZ$ in $cm$.