10. The angles of a quadrilateral taken in order are $x^{\circ}, 5 x^{\circ}, 2 x^{\circ}$ and $4 x^{\circ}$. Which of the following is the quadrilateral?
A kite
$\mathrm{B}$ parallelogram $\mathrm{C}$ rhombus
D arrowhead
E trapezium
10. E The sum of the interior angles of a quadrilateral is $360^{\circ}$, so $x+5 x+2 x+4 x=360$, that is $12 x=360$. Therefore $x=30$ and the angles of the quadrilateral, taken in order, are $30^{\circ}, 150^{\circ}$,
$60^{\circ}$ and $120^{\circ}$. The diagram shows the shape of the quadrilateral.

Since $30+150=180$, we see that $A B$ and $D C$ are parallel. Since it has no equal angles, it is not a rhombus or a parallelogram so it is a trapezium.