Can anyone help me with this question?

13

Step-by-step explanation:

Since this is a right triangle, you can use the Pythagorean Theorem.

The side y would be the hypotenuse.

Plug it in:

Isolate y:

y =

Solve:

y = 13

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.