Ihave 4 factors. three of my factors are 1, 2, and 6. what is my fourth factor?

The 4th factor would be 3. You would find this out through a factor tree. If you don't know the original number when you start you look at your numbers. A factor of 1 usually goes with the highest number, assuming that the number 6 is the highest factor, that would be the original number. As 2 is the other known factor than we know that 3 has to be the last factor, because 2 x 3 = 6. It cannot be the number 12 because then there would be 6 factors not the needed 4.

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.