Cut the triangle
After the triangle has been drawn, cut it out with the help of a scissor carefully.
Mark the Diagonal line
Using a ruler and marker, carefully draw a visible line along the diagonal edge of the triangle cut. This line should be about half inch thick.
The Spirals and triangle base
If the pencil's movement is observed, it can be clearly seen that the number of spirals around the pencil is equal to the base of the triangle; that is, 4 inches. This shows that an inclined plane which is 4 inches above the ground will do the same job of a screw with 4 spirals.