Steps of Construction:
Construct a line segment AB
Considering A as centre and any radius, construct an arc which intersects AB at the point C
Considering C as centre and same radius, construct an arc which intersects the previous arc at the point D
Considering D as centre and same radius, construct an arc which intersects the arc in step 2 at the point E
Considering E and D as centres and radius more than half of ED, construct arcs which intersect each other at the point F
Join the points AF which intersects the arc in step 2 at the point G
Considering G and C as centres and radius more than half of GC, construct arcs intersecting each other at the point H
Join AH which intersects the arc in step 2 at the point I
Considering I and C as centres and radius more than half of IC, construct arcs which intersect each other at the point J
Join AJ
Therefore, we know that ∠JAB = 22.5o
