Track quiz
Each row is a check you can run with a compass.
| Idea | The check |
|---|---|
| Exact, not neat | Measure every side. All the same means it passes. |
| What a circle is | Measure from the centre to points on the curve. All the same. |
| Across the middle | Does the line pass through the centre? Then it is the diameter. |
| Carrying a length | Set the span on the length itself. Do not read a ruler. |
| Square corners | Mark equal distances on both arms. Measure the gap. |
| Steps in order | Ask what a step needs. Is it there yet? |
A four-sided figure has sides of 40, 40, 40 and 42 mm. Are all its sides equal?
What is a circle?
A circle has a radius of 25 mm. What is its diameter?
A line has both ends on a circle. It misses the centre. Is it a diameter?
Why copy a length with a compass and not a ruler?
Marks are 30 mm out on both arms. The gap is 42 mm. What is the corner?
You want to draw a rectangle. The base is not ruled yet. Can you draw the whole rectangle now?
Chapter 8 is called Playing with Constructions. Read it with your compass on the desk.
Next: Symmetry — fold lines, and shapes that match after a turn.