The instructor tells children the following:

• A triangular prism is formed by adding a third dimension to a triangle.
• Triangular prisms are drawn in a similar manner as rectangular prisms.

The instructor tells children to draw a triangular prism as follows:

• Draw the front face.
• Choose the center of vision or eye point and draw the receding lines to it.
• Choose the thickness or depth and draw the farther face.

Children study the image and complete the following drill work:

1. Draw a right triangular prism below and at the left of the eye.
2. Draw a right triangular prism below and at the right of the eye.
3. Draw two right triangular prisms, one below and at the left and one below and at the right of the eye.
4. Draw an acute triangular prism at the right of the eye.
5. Draw an acute triangular prism at the left of the eye.
6. Draw an obtuse triangular prism below the eye.