What is the constant of proportional

The constant value (often written k) relating amounts that rise or fall uniformly together. It is the ratio of the amounts y and x: k = y/x. Put another way: y = kx.

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.

the weight of the object inside the box!