Had the technical
drawing for industry, but also had for the science like for optics in the
physics and in the Chemistry like to explain the behavior of the gases in a
tank.
Technical
drawing uses geometry.
To do a
project 3d or 2d you will need a square the same that esquadro, a ruler, to measure,
and make perfect corners of squares. And if you use scale a calculator.
The project
be in 3d is important for the cut scheme of montage and 2d for scheme of cut.
The project
of the picture shown only shows the dimensions that the object and not the cut
yet because I even don’t know what material will be used, like MDF, wood,
cardboard (this one that had many kinds).
There is
planes in the 3d and only one plan in the 2d picture, in the 3d had the plan
that are parallels and plans that are perpendicular, and also for the figure shown
had the plas that is of the intersection or I would had a parallelogram and not
a magazine holder. For The draw of the object is very important the right
angles. So the 3d picture had 6 planes the.
The scale
(escala) of the draw is 4,5 and escalas don’t have measurement unit, because is
distance upon distance and they cancel each other and so escalas don’t have
unit of measurement, is in the field of comparisons.
The object
and the image, in the picture you had image and not the object and so what
appear a right angle (angulo reto) isn’t (this is a stretch of other mine explanation),
image isn’t object, so is because image isn’t that in the telescope that you see
image and not object you change the distance in the telescope and changing the distance
you are getting close of a image and not of the real object, so the relation of
the focus is important in the plane of the image, if you don’t understand,
extend your arm and grab the small dot that you see in the lens and is of a 5
inches of your eye, the star is huge and is years of distance of you what is
very close of your eyes is his image, and not the star, the same you can’t say
for the microscope that image is reachable. So distance for image is different of
distance for an object, image don’t knock you down but wait for that carriage
and you be run over. Rute Bezerra de Menezes Gondim