Geometry: triangulation for measuring a lot/yard

[Dave Britten]

I'm trying to get the hang of the Prime's geometry app, and I'm not seeing an obvious way to handle this particular scenario.

Suppose you're measuring a yard or lot for some landscaping or whatever, and you can't be certain that it's truly rectangular (i.e. right angles). But you can at least assume you have straight line borders to work with - or you're at least going to treat them as straight. So first you designate one of the corners as (0, 0), say the SW corner for the sake of example. Then you measure the length of the southern border of the lot, and create a triangle with one of the sides (0, 0)-(x, 0), where x is the length of that southern border. Then you measure the distance from the NW corner to both the SW and SE corners, and set these as the lengths of the sides of your triangle. Repeat for NE to SW and SE, and fill in a line segment from NW to NE.

On the Casio geometry app (don't hate, it's actually pretty decent), you can pretty much do as described: throw a triangle on the page, manually set and lock one of the corners to (0, 0), set another to (x, 0), then set the lengths of the other two sides as measured, and it will adjust the coordinates of the NW corner as needed to fit your constraints.

What's the Prime way to tackle this kind of problem? I'm assuming you'd define points at (0, 0) and (x, 0), define a segment between them, but then what?

Tangent (har har) question: can Prime geometry files be exported to something that could be opened with, say, Visio?