The ability to do model of the truncated pyramid can be required at production of some metal details or building constructions. The model of the usual pyramid which is a polyhedron in which basis the polygon lies and side sides is the cornerstone of such model represent triangles. At the truncated pyramid side sides are trapezes. By quantity of corners the truncated pyramids, just as usual, are triangular, quadrangular, etc.
It is required to you
- - ruler;
- - protractor;
- - paper;
- - pencil;
- - glue;
- - wire;
- - passatizh;
- - soldering iron.
Instruction
1. Make development of a full pyramid. Draw the basis. If you build the regular triangular or quadrangular pyramid, draw an equilateral triangle or a square with the set or any parameters. For creation of a pyramid with other quantity of sides or for the wrong pyramid at first calculate all parties and corners of the basis. It is possible that the compasses for this purpose are required, it is more convenient to draw some polygons, having taken a circle as a basis.
2. Calculate heights of side sides. At regular pyramids all of them are equal among themselves and fall from top on the middle of an edge between the basis and this side. Find all middle of such edges and carry out through them perpendiculars in the direction from the basis. Postpone the set or any size of height from points of intersection and put the end. Connect this point to the basis corners belonging to this side. At the wrong pyramid each height is calculated separately.
3. The moment came to cut top of future pyramid. Define at the height of one from sides through what point there will pass a secant the plane. Draw the straight line parallel to the relevant party of the basis through this point. Carry out just the same pieces also on other sides. The top parts of sides can be erased.
4. It was necessary to draw the top basis. You already have one of lines - it is one of those pieces which you cut the top part of each side. Having taken it for one of the parties of the top polyhedron, draw this polyhedron. It is similar to the basis, but it is less by the size. Development is ready.
5. To turn development into a pattern, it is necessary to draw allowances for gluing together. Draw on one allowance at each side side, having arranged them clockwise or against. Do the top allowances on which the top basis will be pasted not at side sides, and at the top plane on all its parties. Cut out the truncated pyramid, bend it on all necessary lines and stick together.
6. For wire model of a pattern it is unnecessary, there is enough development. Cut off the piece of a wire equal to basis perimeter. Bend it in the form of a polyhedron of the necessary form and solder the ends of a wire. In the same way make the top basis. Cut the pieces of a wire equal to side edges. Solder them to the bases. Correct model that all edges were straight lines.