Lesson 2:
3D geometric shapes.
Before starting to represent the views of more complex figures we are going to review the main 3D geometric shapes that exist. Knowing them, and being able to represent their views will help you a lot when trying to draw the views of other objects. If you don’t remember what are the views (front, side and top) of a figure I recommend you to have a look at this page: The views of an object – 1st of ESO.
The geometric shapes we are going to represent are:
- Cubes, prisms y pyramids: which belong to a particular group inside the 3D geometric shapes called polyhedrons. A polyhedron is a 3D geometric shape made of flat faces.
- Cylinders and cones: which are geometrical shapes with some curved faces, reason why they are not polyhedrons.
Drawing the views of a cube.
A cube is a very particular polyhedron with 6 square faces that are exactly the same. Therefore, to define a cube knowing the length of one of its edges is enough. In this case, we are going to represent a cube whose edges have a length of 30mm:
Below, the faces that can be seen from each of the views have been colored:
Front view
Side view
Top view
And the following gifs allow us to see how each of the view must be represented:
Front view
Side view
Top view
Obviously, in the case of a cube, the three views are squares of the same size:
Drawing the views of a prism.
A prism is a polyhedron with two equal and parallel faces called bases and a certain number of lateral faces that are parallelograms. Depending on the kind of polygon of its bases a prism receives a particular name: triangular prism (if its bases are triangles), square prism (if its bases are squares), pentagonal prism (if its bases are pentagons)…
In this case we are going to draw the views of a rectangular prism (its bases are rectangles of 10x20mm) with a height of 30mm:
Below, the faces that can be seen from each of the views have been colored:
Front view
Side view
Top view
And the following gifs allow us to see how each of the view must be represented:
Front view
Side view
Top view
As you can see, in a rectangular prism, all three views are rectangles, however, as it happens here, the sides of those rectangles might all be different.
Drawing the views of a cylinder
A cylinder is a geometric shape with two circular faces of the same size and parallel, called bases, and a lateral curved surface. Now we are going to draw the views of a cylinder with a height of 30mm and whose bases are circles with a diameter of 20mm.
Below, the faces that can be seen from each of the views have been colored:
Front view
Side view
Top view
And the gifs below allow us to see how each of the view must be represented:
Front view
Side view
Top view
Therefore, the view of the cylider correctly placed are:
Drawing the views of a pyramid.
A pyramid is a polyhedron with a base and several triangular lateral faces that connect in a point called the apex. The base can be any kind of polygon, regular or not, and depending of it the pyramid will receive one name or another: triangular pyramid (if the base is a triangle), square pyramid (if it is a square), pentagonal (if it is a pentagon)…
In this case will represent the views of a rectangular pyramid with the following dimensions:
Below, the faces that can be seen from each of the views have been colored. Realize that in this case from the top view the four triangular faces can be seen:
Front view
Side view
Top view
And the gifs below allow us to see how each of the view must be represented:
Front view
Side view
Top view
Therefore, the view of the pyramid are:
Drawing the views of a cone.
A cone is a geometric shape with an only circular base, a lateral curved surface and an apex. Think how the views of a cone look like and try to draw the vies of the following cone:
