Step 1. Thin lines we draw a triangle, then in a triangle we draw parallel lines to the parties at a certain distance.
Step 2. Again we draw parallel lines, as on the picture.
Step 3. Let's direct a triangle contour fat lines now. We lead round the main contour of a triangle, thus edges the stesyvay.
Step 4. We look at the picture and we repeat the line in the future 3triangle d.
Step 5. We draw the same form the line, only from below a triangle.
Step 6. Dorisovyvayem last 3D line of a triangle.
Step 7. We erase excess lines. In pure form such has to turn out a 3D triangle.
Step 8. We paint over a pencil of the party of a 3D triangle, as on the picture.
Watch still a 3D cube, a 3D cube-rubik, a 3D rectangle, a 3D trapeze, 3D illusion.