I am importing many of models created by moving objects in another environment, for sure not accurate way. The models constructed as a result are messy, full of unwanted lines and geometry. Anyway they are necessary for me to get exact dimensions of main shapes of the object. I am quite a beginner, searching the easiest way how to reduce that added geometry. I hope that the picture here is enough describing the problem. My tries to reduce geometry simply by deleting lines end by messing up the whole thing, which happens sooner if the geometry is more complex. In fact the models themselves are quite simple. What i need, is, to be able to define basic geometry from inside and outside by clicking the main points, e. g. to define a cube by clicking 4 times inside and 4 times outside. This way I could reconstruct the original idea. I do not know if this is possible to do and if so, how. Any other help very appreciated, suggested addons or techniques, some simple tutorial. I can provide model itself for demonstration things on it as well. Sorry if my English is not perfect as I am not native speaker.