Construct an angle of measure ${300}^o$ using compasses and ruler.

$1.$Construct a circle with centre at $O$ with a radius of $OA=7$cm

$2.$ With the same distance draw an arc from the point $A$ and name the point where the arc intersects with the circle as $E\therefore \angle AOE={60}^{\circ }$

$3.$With the same distance draw an arc from the point $E$ and name the point where the arc intersects with the circle as $F\therefore \angle AOF={120}^{\circ }$

$4.$With the same distance draw an arc from the point $F$ and name the point where the arc intersects with the circle as $G\therefore \angle AOG={180}^{\circ }$

$3.$With the same distance draw an arc from the point $G$ and name the point where the arc intersects with the circle as $H\therefore \angle AOH={240}^{\circ }$

$4.$With the same distance draw an arc from the point $F$ and name the point where the arc intersects with the circle as $G\therefore \angle AOG={180}^{\circ }$

$5.$With the same distance draw an arc from the point $H$ and name the point where the arc intersects with the circle as $B\therefore \angle AOB={300}^{\circ }$