To construct an angle of 45°, the given steps can be followed
1. Let us draw a ray OA
2. Considering O as a centre with any radius, draw an arc DCB that cuts OA at B.
3.Considering B as a centre with the same radius, mark a point C on the arc DCB.
4. Considering C as a centre and the same radius, mark a point D on the arc DCB.
5. Now let us take C and D as the centre, draw two arcs that intersect each other with the same radius at P.
6. Now the ray OP is joined which makes an angle of 90° with OP is formed.
7. Considering B and Q as centre let us draw the perpendicular bisector which intersects at the point R
8. Draw a line that joins the point O and R
9. So, the angle formed ∠ROA = 45°
From the construction,
∠POA = 90°
From the perpendicular bisector from the point B and Q, which divides the ∠POA into two halves. So it becomes
∠ROA = ½ ∠POA
∠ROA = (½)×90° = 45°