### Theory:

In your earlier classes, you learned about the line segments and basic types of angles. Now in this lesson, we are going to construct a following get proper visual understanding.
• Perpendicular bisector of a line segment
• Angle bisector of an angle
• Construct of special angles without protractor
The construction of perpendicular bisector of a line segment:

Make a note of the following steps to construct a perpendicular bisector of the line segment $$AB = 10 cm$$.

Step 1: Draw a line and mark two points $$A$$ and $$B$$ on it. That is, $$AB = 10cm$$.

Step 2: Make $$A$$ as centre and radius more than half of the length of $$AB$$, draw two arcs of same length, one above $$AB$$ and one below $$AB$$.

Step 3: Now take $$B$$ as centre, draw two arcs with the same radius to cut the arcs drawn in step $$2$$. Mark the points of intersection of the arcs as $$C$$ and $$D$$.

Step 4: Then, join $$C$$ and $$D$$. The line $$CD$$ will intersect $$AB$$. Mark the point of intersection as $$O$$. $$CD$$ is the required perpendicular bisector of $$AB$$. Now measure the distance between $$A$$ and $$O$$ and $$O$$ and $$B$$. We have $$AO = OB$$ $$= 5 cm$$.

Thus, we have constructed the perpendicular bisector of $$AB$$ and this perpendicular bisector divides the line $$AB =10 cm$$ two parts $$AO$$ $$= OB$$ $$= 5 cm$$.