 Hello and welcome to the session. In this session we will discuss some constructions. First we shall discuss how to construct the bisector of a given angle. Suppose that we are given any angle ABC and we need to construct the bisector for this angle. This is the angle ABC. We need to construct the bisector for this angle. Our first step of construction would be taking B as the center and any radius we draw an arc to intersect the rays BA and BC. So we have drawn this arc which intersects the ray AB at the point E and ray BC at the point D. Now in the next step we take B and E as the center and radius more than half of DE. We draw arcs to intersect each other. So when we take E as the center and radius more than half of DE we have drawn this arc. And then on taking D as the center and radius more than half of DE we have drawn this arc. And suppose we name this point of intersection of the two arcs as F. Then in the next step we draw the ray BF. So we have drawn the ray BF. This ray BF is the required bisector of the angle ABC. Next we discuss how we construct the perpendicular bisector of a given line segment. Consider a line segment AB is given. We need to construct the perpendicular bisector for this AB. This is the line segment AB. In the first step what we do is we take A and B as the centers and radius should be more than half of AB. We draw arcs on both sides of the line segment AB such that they intersect each other. In this way let this point of intersection be P and this point of intersection of the two arcs be Q. In the next step we shall join PQ. Let this PQ intersect the line segment AB at point M that is this is the point M. Then this line PMQ is the required perpendicular bisector of AB. Next we learn how to construct an angle of 60 degrees at the initial point of a given ray. Consider that we are given a ray AB. This is the ray AB. We will construct an angle of 60 degrees at the initial point of this ray that is at the point A. In the first step we take A as the center and some radius and then we draw an arc of a circle which intersects AB. So as you can see we have drawn this arc. Let this point of intersection of the arc with the ray AB be point D. In the next step we take D as the center and with same radius as before we draw an arc intersecting the previously drawn arc. Let this point of intersection of the two arcs be named as E then we draw the ray AC passing through the point E. That is a next step of construction is draw ray AC passing through the point E. This is the ray AC through the point E then this angle CAB is 60 degrees. Therefore angle CAB is the required angle of 60 degrees. This completes the session. Hope you have understood how we construct the bisector of a given angle, perpendicular bisector of a given line segment and an angle of 60 degrees at the initial point of a given ray.