Abstract
This paper aims at problems of structure in Eucliean space by using Cabri 3D. Cabri 3D is a Software to model these problems. Let us observe properties of structure more easily. And we exploit Cabri 3D to draw figures and design a drawing process. The problem of structure we discuss is the “transitivity of central projection” in three-dimensional space. Since not all triangles with Central Projection have transitivity, so we propose a sufficient condition and discuss some properties. We start from two-dimensional view to three-dimensional view. Further, we discuss locus of three triangles with Central Projection pairwisely.