In the step shown of the construction of a line through a point that is perpendicular to the given line, why must the compass point be placed on points a and b? how would the construction be different if the compass point were placed at random points on the original line?

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.

i dont know sorry

step-by-step explanation: