Originally Posted by
masters Hi sologuitar,
Here's a way. Maybe someone has another. We'll see.
Draw the segment from M to the origin (0, 0). Find its distance using the distance formula.
You should find it to be $\displaystyle \frac{\sqrt{s^2+r^2}}{2}$
Find the coordinates of the midpoint M on the hypotenuse using the midpoint formula.
You should come up with $\displaystyle \left(\frac{s}{2}, \frac{r}{2}\right)$
Now find the distances from M to the vertices on the hypotenuse and you'll see they're the same as the distance from M to the origin.