Perpendiculars through a point, on the line and off it
- Which picture can you start from — 3 tasks
- The first arc — 3 tasks
- Perpendicular at a point on the line — 3 tasks
- Perpendicular from a point off the line — 3 tasks
- Going Deeper — 6 tasks
- Practice — 23 tasks
- Summary — 2 tasks
- Cool-down — 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.
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Perpendicular Through a Point: The Line Asked For, a Bisector, or Another Line? — Cut & Glue Sort 25 minutes, including the cutting · 5 sheets
12 triangles, each asking for the perpendicular to a named line through a named point, with somebody's finished compass marks stopped before the line: sort each by what the marks are built for — the line asked for, the perpendicular bisector of the side instead, or a perpendicular to a different line, the error no check catches.
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Perpendicular Through a Point: Do the Marks Prove the Line? — Mystery Picture 25–35 minutes · 4 sheets
25 strangers' finished attempts at the perpendicular through a point, on the line and off it, every arc left on and no numbers: fill the square if the marks prove the line, leave it white if they do not — a pair opened equal on the line, a reset compass, a line ruled by eye, the drawn segment bisected instead, or a compass that would not reach.