There must be some simple geometric trick for this! (Or maybe it’s calculus )

I have two *similar* right triangles (and with the same orientation). I want the larger to be perfectly “outside” of the smaller; but **not centered**. I need the three sides of the larger to be equally offset; equal aligned distance along their perpendiculars.

(Centering the two is elementary and does not solve the problem. Also, I am not using OffsetCurve because that is not the requirement; the geometry is what it is.)

By co-locating the hypotenuses, and then translating one triangle along a 45-degree path (using ortho snaps), I can easily keep the two adjacent sides equally offset from the stationary triangle (A and C). There MUST be some point along this translation path where **all three offsets are equal.** That is obvious.

But how? Is there a way to do this exactly using Rhino’s lovely suite of tools; snaps, curve tools, etc?

I tried many things. I have been using Rhino for 25 years. Once upon a time, I took calculus and geometry courses, but that is long forgotten. Below is my terrible (non)solution. This is not right. I want EXACT. This just gets within my tolerance.

This is the top-left corner. I made circle **a** with radius to left side offset, circle **b** with radius to right side offset, and 45-degree line **d**. Then I move outer triangle c along that 45-degree line to its midpoint. And repeat until the offset dimensions are within tolerance. This is embarrassing!