The ASA and AAS criteria (by rigid motions)
- Send one message — 3 tasks
- The side between two angles — 3 tasks
- Three moves, and the last corner — 3 tasks
- Move the tick, change the name — 3 tasks
- What pins the last vertex — 3 tasks
- Practice — 25 tasks
- Summary — 2 tasks
- Cool-down — 6 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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ASA, AAS, or Not Proved? — Cut & Glue Sort 25 minutes, including the cutting · 5 sheets
12 pairs of triangles marked with arcs and ticks, sorted into ASA, AAS and not proved. The last row holds the trap almost nobody prints: two equal angles and a ticked side in each triangle, with the ticks in different places, so the triangles are not congruent.
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ASA, AAS, or Not Proved? — Answer Maze 10–15 minutes · 4 sheets
8 boxes on one page, each a pair of marked triangles or three written lines: is it ASA, AAS, or not proved? The wrong answers are the two mistakes this lesson exists to stop — mixing up ASA and AAS (often by reading the order of the lines), and taking two angles and any side as enough. The row of box numbers at the foot is the check.
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Is the Side Between the Angles? ASA or AAS — Mystery Picture 25–35 minutes · 4 sheets
25 squares, each one triangle with two marked angles and one marked side, drawn or described: fill the square if the side joins the two angles (ASA), leave it white if it does not (AAS). Triangles turned every way, right angles as one of the two angles, and sentences whose word order points to the wrong rule. When every square is right, a letter appears.