Hand-tool lesson · Measure and mark

Compass

Draw a circle by keeping a fixed distance from a center point.

Watch · practice · showInstructor-supervised
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In this lesson

Know the tool

Maplewoodshop photograph of a compass with a metal center point and pencil leg.

Your goal: Draw and check a circle with a 1-inch radius.

A drawing compass has a center point and a pencil leg. The distance between their tips sets the radius, the distance from the center to the circle.

Identify the center point, pencil tip, hinge, and any adjustment or locking control on your compass.

Watch and prepare

At your station

  • A compass with a secure pencil, ruler, paper, and instructor-approved backing.
  • Eye protection and a clear area for the sharp center point.

Demonstration and setup

  • Watch the instructor set and hold the opening, place the center point, and turn the compass without moving the center.
  • Keep fingers away from the point; close and carry the tool as demonstrated.
  • Support the paper on the approved backing so the point does not reach a hand or damage the bench.

Practice

Start after the demonstration and the instructor's setup check. Stop and ask for help if the work moves or the tool does not behave as demonstrated.

  1. Mark the center.

    Make a small center mark with room for the whole circle. Stabilize the paper on its backing as demonstrated.

  2. Set the radius.

    Use the ruler to set the tip-to-tip distance to 1 inch. Check that the pencil and opening stay secure.

  3. Draw the circle.

    Place the center point gently on the mark. Rotate the compass by its demonstrated grip, keeping that point still and the opening unchanged.

  4. Check the result.

    Measure from the center to the circle in several directions. Then measure across the center from one side of the circle to the other.

Show your skill

Show the instructor these observable results before using the skill in a project:

  • The center stays in one place and the circle closes without a spiral.
  • Center-to-circle measurements are about 1 inch, within the instructor's marking tolerance.
  • The distance across the center is about 2 inches; you can distinguish radius from diameter.

Check your understanding

If the radius is 1 inch, what is the diameter?

Reveal the explanation

2 inches. The diameter passes through the center and is twice the radius: 2 × 1 inch = 2 inches.

Answer aloud or on paper, then compare with the explanation.

Use the skill

Use the skill again at the next instructor-approved practice station.

Maplewoodshop materials adapted with permission. Images © Maplewoodshop. Practice tasks and learning checks by STEM Guides. Maplewoodshop.