Hi fellas!

I'm working on a really large and complex model and I've come across with what, at first, may seem a easy problem.

Well, I'm trying to draw a right triangle from the hypotenuse and one side, but I know no angles (except the 90º one, of course).

I've tried to draw a circle with the known side as the radius, with the center on one end of the hypotenuse and then draw a line from the other end tangent to the circle, but this method is slow and inaccurate.
Then I drew a random right triangle and by using pythagoras theorem scale it on the second side axis, but I'd have to do this 73 times in the model and I'd go crazy...

Do you know any plugin or easier way to solve this?

Thank you in advance,

C.