Fix Dark Spots On Screen

Scales
is the ratio between a drawing and the real object. Scale =

as drawing / actual measurement.

can be natural, reduction or enlargement, depending on the dimensions of the drawing the same, lower or higher than the object being represented.

Examples:

reduction:
1 / 100 means that 1 cm on the drawing is 100 cm or 1 m in reality.

1 / 25 means that 1 cm on the drawing is 25 cm or ¼ m in reality. If we divide 1 / 25 = 0.04, ie 1 m to 1 / 25 scale is 0.04 m, that is 4 cm.

expansion:
1 / 200 means that 1 cm on the drawing is 200 cm or 2 m in reality.
½ cm (5 mm) is 1m.
¼ inches (2.5 mm) is 1/2m (50 cm).

Graphic scale and universal triangle scales
If on a line will mark the cm scale 1 / 100. If we draw a vertex M radiation incident on the vertical through the point 0, we can draw different scales:
On the vertical lifting a 0.5 point cut to the 1 st line m as the point P. Here goes the scale 1 / 200. In section 2
drawing a vertical cut at 1 m as the first line point T. Here goes the scale 1 / 50. In Section 4
get the scale 1 / 25, by 5 we get the scale 1 / 20, by 10 we get the scale 1 / 10, by 100 we get the natural scale 1 / 1, etc.
We subdivide each unit of every scale, from 0 to 1 in 10, for the contraescala.
















A figure is transformed into another by a dilation of ratio 5 / 8. To construct homothetic figures, it is a segment from the red figure, for example, and the rule is divided into eight units. In eight cases the join point with the vertex of a figure, and five do a line parallel to the above until it intersects the red side of the polygon.
With this we have divided the segment having a size proportional to eight in 5 / 8, that is, we took five pieces of eight.
As we know that the dilation preserves the parallelism by this point we figured we make a parallel to the side of the figure, knowing that all the vertices are arranged in lines through the projection center of dilation, which in this case is the common vertex of the two figures.
















A homothety from the center which is common vertex of two triangles, becomes a triangle in another because of 7 / 4. Dilation was considered positive if homologous points on the same side to the center of projection, as in this case. If the center of projection is between the two figures is negative dilation.