Hi sologuitar,

Here's a way. Maybe someone has another. We'll see.

Draw the segment fromMto theorigin (0, 0).Find its distance using the distance formula.

You should find it to be

Find the coordinates of the midpointMon the hypotenuse using the midpoint formula.

You should come up with

Now find the distances fromMto the vertices on the hypotenuse and you'll see they're the same as the distance fromMto the origin.