Carol makes a scale drawing of her school using a scale of 8cm: 12m. if the length of the playground on the scale drawing is 12.4 cm, what is the actual length of the playground?

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.

ok thats very interesting