Copying a segment and copying an angle
- The eye against the compass — 3 tasks
- What a drawn arc promises — 3 tasks
- Copying a segment — 3 tasks
- Copying an angle — 6 tasks
- Why the copy is exact, and what a check reaches — 6 tasks
- Practice — 26 tasks
- Summary — 2 tasks
- Both constructions, and what each arc is for — 3 tasks
Classroom activities
Things a class does rather than writes on. Each one is a finished PDF: print it, cut it up if it says so, and hand it round.
-
Compared With the Compass: What Do the Marks Prove? — Cut & Glue Sort 25 minutes, including the cutting · 5 sheets
12 pairs of segments and angles compared with the compass instead of a ruler, the marks left on, sorted into proved by the marks, shown false by the marks, and no mark says either way — where a pair drawn exactly equal, or cut by arcs of two different openings, still proves nothing.
-
Copying a Segment and an Angle: What Is the Next Move? — Answer Maze 10–15 minutes · 4 sheets
One page and nothing to prepare: 8 copies of a segment or an angle stopped half-way, and at every box one question — leave the compass as it is or reset it, and where its point goes next — with the answer the classic mistake gives leading to a box that sends you back.
-
Copying a Segment and an Angle: Do the Marks Prove the Copy? — Mystery Picture 25–35 minutes · 4 sheets
25 strangers' finished copies of a segment or an angle, every arc left on and no numbers: fill the square if the marks prove the copy is exactly the original's size, leave it white if a mark shows a move went wrong — or if nothing shows the opening came from the original at all.