Section of a polyhedron is the plane which crosses its sides. Depending on basic data there is a set of methods of creation of section. Let's consider a case when three points of section lying on different edges of a polyhedron are given. In this case for creation of section straight lines through the points lying on one straight line are drawn then direct crossings of sides with the section plane are looked for.
Instruction
1. Let ABCDA1B1C1D1 cube be given. It is necessary to carry out section through points M, N and L lying on his edges. Let's connect points of L and M. The straight line of ML and an edge of A1D1 lie in one ADA1D1 plane. Let's cross them, we will receive X1 point. A piece of ML - crossing of the plane of section with AA1D1D side.
2. The point of X1 belongs to A1B1C1D1 plane since lies on direct A1D1. The straight line of X1N crosses A1B1 edge in K point. KM piece – crossing of the plane of section with AA1B1B side.
3. The straight line of ML and an edge of D1D lie in one AA1D1D plane. Let's cross them, we will receive X2 point. Direct KN and an edge of D1C1 also lie in one A1B1C1D1 plane. Let's cross them, we will receive X3 point.
4. Let's construct direct X2X3. This straight line lies on the CC1D1D plane and crosses an edge of DC in a point P, CC1 edge in point T.Soediniv of a point of L, P, T and N we will receive MKNTPL.Takim section in the way it is possible to construct the section of any polyhedron.