Triangle Forge

Both triangles are floppy — drag corners, then add pieces

the kit — drag a piece onto the left triangle · or tap-then-tap · max 3

forge collection · 0/7

how it works

Place pieces on your forge — the twin copies them. Tune any value: if the rule holds, OVERLAY always matches. Move a twin piece to a different spot, or wiggle SSA / resize AAA — same pieces, different triangle.

For the teacher

Students reach the congruence rules by building — not by being told.