Explanation:
I cannot draw here.
but the only problem might be to understand the key word : perpendicular.
it means the resulting line is crossing our touching the original line with a right (90 degree) angle.
that is all that is to it.
oh, and a bisector is a line crossing or touching the original line right in the middle of the original line.
I am sure you have rulers that provide right angles when drawing a line, and that allows you to measure the length of a line and so find is middle.
or do you really need to "construct" this ? in the sense of using also a compass and drawing cycles that cross each other and then you connect the crossing points with a line ?
if that is the case :
you can "construct" a right-angled line in the middle between 2 points by drawing a circle for each point. the center of a circle is one point, and the radius is the distance to the other point.
so, both circles go through the other point. and where the 2 circles cross each other (there are 2 crossing points) mark these points, and then connect them.
and there you go, you have a line in a right angle to the original line that goes through the middle of the original line.
so, for problem 1 define 2 points on either side of B with the same distance to B.
then follow the described process for these 2 points.
for problem 2 you need to double the line AB out to the left of A, and then again to the right of B. you can do that by drawing the 2 circles in A and in B, and then extend AB to both sides until the line touches the circles.
now you have 2 points left and right of A (one of them is B) to use the procedure for the perpendicular line through A. and then again 2 points left and right of B (one of them is A) to use the procedure for B.
for problem 3 you use the procedure with the end points of each of the 3 lines, giving you 3 perpendicular lines through the middle of their corresponding original lines. and you make them long enough that all 3 lines meet inside the triangle.