How can a square projection be shaped into a regular pentagon

No solution! To project into a pentagon, the projection surface must pass a vertex of the square, and a sketch must be drawn, and it is obvious that you will not get a regular pentagon.

I understand projection as the shadow left by an object on the plane behind the object by lighting it in parallel, and if so, then.

The projection of parallel lines is still parallel, and the cube has three sets of parallel flutes (four in each group), so the sides of its projection have at most three different directions, but the sides of a regular pentagon have five different directions, so it is impossible.

Rotate the cube at a 30-degree angle and you're good to go!

Use one of the vertices of the cube as a support, and after fixing, it will be projected vertically from any of the upper edges, which should not be a regular pentagon.

It should not be a regular pentagon.

Pentagons are not OK, there are limitations.

The pentagonal shape seems to be okay, but the positive one is a little difficult, I don't understand.

If you are like this, then directly measure b-b'distance. Then use a right-angled triangle ruler with a right-angled side and b-b'Coincident, then use a ruler to perpendicular to the other right-angled side of the right-angled triangle, and then move this to be a right-angled triangle. Draw b-b through the vertices of the pentagon'For line segments of the same distance, you can connect the vertices of five line segments.

There is a line ae, で by a face-changing method, a machine-made book.

Hair I good v hair dryer maybe, hahaha.

Take a piece of A4 paper.

Turn the paper over and fold the straight edges to align with the paper edges underneath.

Use a handmade knife to cut off the rectangle along the diagram.

Take the rectangle, and the rest is the square.

Measure the width of the rectangle, the width of the rectangle is used as the length of the side of the square, and the extra ones are just cut off.

The degree of each angle of the square pentagon is: 360 5 = 72°, according to this degree can be folded into a regular pentagon.

In the above way, you cut the hexagonal from the top surface diagonally to the vertex near a vertex, and cut out from the bottom near the opposite vertex.

Use a plane to cut a cube, and the section may be a triangle, a quadrilateral, a pentagon, or a hexagon. A planar truncated cube, since the cube has six faces, the cross-section cannot be heptagonal.

Truncate the cube with a flat surface.

Truncate the cube with a plane. The following triangles, rectangles, squares, pentagons, pentagons, hexagons, hexagons, diamonds, and trapezoids can be obtained.

Volume The volume of the cube (or the volume of the cube) = edge length edge length edge length; Let the edge length of a cube be a, then its volume is:

v=a a a a or equal to ;

First take the diagonal of the upper bottom surface, calculate, and obtain, the root number is 2 times the length of the edge.

The edge that intersects the diagonal line is the edge perpendicular to the upper and bottom surface, and can form a right-angled triangle, and the hypotenuse of this right-angled triangle is the body diagonal, according to the Pythagorean theorem, the body diagonal = 3 times the length of the edge.

1. Draw a line on any two adjacent sides of a square to become a pentagon (be careful not to connect diagonal lines).

2. A square cannot become a hexagon by drawing a line, and it needs to be drawn at least twice to become a hexagon.

Draw a line on any two adjacent sides of a square to form a pentagon (be careful not to connect diagonally).

Draw a line on any two adjacent sides of a pentagon to form a hexagon (be careful not to connect diagonally).

The answer is as follows:

1. Center projection: The projection formed by the outward scattering of light from a point is called the center projection, and the size of the projection changes with the change of the distance between the object and the projection center.

2. Parallel projection: The projection formed under the illumination of a parallel ray of light is called parallel projection. In parallel projection, when the projection line is facing the projection surface, it is called orthotropic projection, otherwise it is called oblique projection.

Three, three views of the space geometry.

The rays of light are projected from the front to the back of the geometry to get a projection map, which is called the front view of the geometry; Light rays are projected from the left to the right of the geometry to obtain a projection map, which is called the side view of the geometry; The projection is obtained from the top of the geometry to the bottom of the projection, which is called the top view of the geometry. The front, side, and top views of the geometry are collectively referred to as the three views of the geometry.

Fourth, the rules for drawing three views:

The rule of drawing three views is that the front side is the same height, the front view is the same length, and the top side is the same width, that is, the front view and the side view are the same high, the front view and the top view are the same length, and the top view and side view are the same wide;

When drawing three views, it should be noted that the blocked contour line is drawn as a dashed line, the visible contour line and edge are represented by a solid line, the invisible contour line and edge are represented by a dashed line, and the dimension line is marked with a thin solid line; d for diameter, r for radius; When the unit is not indicated, it will be counted as mm;

For simple geometry, such as a brick, a positive projection to two planes perpendicular to each other will truly reflect its size and shape Generally only draw its front view and top view (second view) For complex geometry, three views may not be enough to reflect its size and shape, and more projection planes are needed.

A three-dimensional figure surrounded by six identical squares is called a cube. A straight parallelepiped with a square side and bottom surface is called a cube, that is, a hexahedron with equal edge lengths, also known as a "cube" or "regular hexahedron". Cubes are special cuboids.

Dynamic definition of a cube: A three-dimensional shape obtained by translating the side length of a square perpendicular to the direction of the face on which it is located.

Cut a cube with a plane, and since the cube has six faces, the section cannot be heptagonal.

How else to expand? Our production team asks for 30 words + OK. I'm already trying to meet your requirements.

What can be expanded will naturally expand. I hope you can also review the questions well, what kind of questions can be asked to be more extended, and what can be answered in place. It's all work, and I hope to be able to respect and understand each other, thank you.