Question

draw the angles of the following measurements using a compass:(a)45/2degree(b)45degree

Answer 1

this is only possible practically.

Answer 2

1). Use ruler and draw a Line segment OB of any convenient length.
2). Now use compass and open it to any convenient radius. And with O as center , draw an arc which cuts line segment OB at X
3). Again use compass and opened to the same radius (as of step 2). And with X as center , draw an arc which cuts first arc at D 
4). Again use compass and opened to the same radius (as of step 2). And with D as center , draw another arc which cuts first arc at C 
5). Again use compass and opened to the same radius (as of step 2). And With C & D as center , draw two arcs which cuts each other at E 
6). Join OE and extent it to A 
7). Above formed angle AOB = 90 Degree 
8). Again use compass and open it to any convenient radius. And with O as center , draw an arc which cuts line segment OB at P and OA at Q
9) Again use compass and opened to same radius (as of step 8).And with P & Q as center and, draw two arcs which cuts each other at point F

10) Join OF and extend to E11) EO is the bisector of Angle AOB 
Therefore, Angle AOE = Angle EOB = ½ of Angle AOB = 45 Degree each


to do 45/2 bisect 45 degree.the angle will be 22.5