Twins look exactly alike! In geometry, two shapes that are EXACT copies of each other — same shape AND size — are called congruent.
🪞Congruent: Two figures that can be placed exactly on top of each other (flipping/rotating is allowed!).
📐SSS Rule: If two triangles have all 3 matching side lengths, they MUST be congruent — no need to check angles!
🔤Matching order matters: Writing △ABC ≅ △XYZ means A matches X, B matches Y, and C matches Z — in that exact order.
🎯Corresponding parts: In congruent triangles, matching sides are equal AND matching angles are equal.
⭕Other shapes: Two circles are congruent if they have the same radius. Two rectangles are congruent if length AND breadth match.
Try this△ABC has sides 4cm, 6cm, 8cm. △PQR has the SAME 3 sides. By the SSS rule, they must be congruent — even without measuring any angles!
Start the challenge ↓