Edges and contact relationships — study worksheet

1. Read the core idea

Identify which boundaries must touch and which remain on the outside of the completed figure. Begin with an unusual long edge, curve, notch, or angle so you have a stable reference. A correct assembly must preserve every piece’s geometry. Check both the join and the outside boundary; one matching edge alone is not sufficient evidence that the arrangement works.

2. Trace the worked example

If a curved edge must remain outside the final outline, a proposed arrangement that buries it at an internal join cannot fit that outline.

Write the steps or relationships that explain the result:

3. Use the method

Mark one distinctive edge and follow its neighbors around the piece in order.

Summarize the method in your own words, with a diagram or labeled units where useful:

4. Record a mistake to avoid

A local match can look convincing while the whole shape remains wrong.

Describe how you will recognize and correct this mistake:

5. Review after practice

Use the mixed practice check linked in the hub. Record the skill you need to revisit and your next study step.