Geometry: setting significant digits

I am creating an activity and am using the geometry tool. I want my students to see angles and sides of triangles are relational. I’ve created a triangle between two parllel lines (to incorporate transversals and angle relationships into the activity). When I move the points of the triangle so the triangle is equiangluar, the measures of the legs are off by a couple hundreths. This will greatly confuse my students as the concept of margin of error will create an additional level of difficulty on top of an already difficult subject for them. I want to restrict the measure to a tenth (1 significant digit). How do I do this?

I think you might be better off using the graphing calculator for this. The geometry tool is pretty basic right now and you aren’t able to use CL with it either.