With compass and a ruler, construct an angle of 22 1 2 ° .

Draw a ray O A using the ruler. Take any convenient radius draw a semi-circle from vertex O .Without changing the measurement in the compass, cut an arc from vertex C at X . With X as centre and same opening of compass cut another arc at K . With K a n d X as centres and radius more than half of K X , draw two arcs intersecting each other at L . Draw ray O E through L from the vertex O to get an angle of 90 ° . Similarly draw the angle bisector of ∠ E O A to get an angle of 45 ° . Now, this angle is again bisected to get an angle of 22 1 2 ° O G is the angle bisector of ∠ A O F . ∴ ∠ A O G = 22 1 2 ° Hence, an angle of 22 1 2 ° is constructed.