The descriptive geometry is base for many theoretical developments in the field of technical drawing. Knowledge of this theory in creation of images of geometrical objects is necessary authentically to express the ideas by means of the drawing.
Instruction
1. It is possible to call a task of creation of the line of crossing for 2 planes basic in the theory of technical drawing. To form the line of crossing for 2 triangles, it is necessary to define the points belonging to both flat figures.
2. For the solution of a task construct two triangles of ABC and EDK in a frontal and horizontal projection. Then carry out through the party of AB in a triangle of ABC auxiliary plane Rn, its horizontal projection. This horizontal plane forms the line of crossing 1-2 with the plane of the second triangle of EDK where points 1 and 2 are on the parties of ED and EK.
3. In the same way find the line of crossing 1 -2 ′ horizontally projecting plane Rn which is carried out through the party of A′B ′ in a frontal projection of a triangle of ABC. Frontal projections 1 -2 ′ and A′B ′ are crossed among themselves and give a point of intersection of M ′, its frontal projection.
4. Draw the communication line from a frontal projection to a horizontal projection and thus find a horizontal projection of a point of M.
5. Define the second point of intersection of the planes of a triangle of ABC and a triangle of EDK for what carry out through the party of DK in EDK triangle the auxiliary Qv plane, its frontal projection. Line 3-4 and line 3 -4 ′ in its frontal projection becomes the line of crossing of the Qv plane with the plane of a triangle of ABC. Horizontal projections 3-4 and DK are crossed among themselves and give N point of intersection, its horizontal projection.
6. Draw the communication line from a horizontal projection to a frontal projection and thus find N point ′, its frontal projection.
7. Connect points of a projection of the line of crossing of MN and the line of crossing of M′N ′. As a result you receive two lines of crossing of triangles of EDK and ABC in their frontal and horizontal projection.