Congruence & Triangles
📋 What it is
Congruent shapes are identical in size and shape; triangles are congruent by rules like SSS, SAS, ASA.
🗣️ Coach says
Congruent means "exact copies" — same size, same shape. For triangles you don't need to check all six parts: shortcuts like SSS (three sides) or SAS (two sides + the angle between) prove it with just three facts.
🧠 Memory hook
Congruent = identical twins. SSS / SAS / ASA = three matching facts are enough to prove it.
😂 Giggle
What did the hypotenuse say after working out?
"I'm the longest side — I've been doing leg exercises!"
😲 Whoa!
Bridges and roofs are built from triangles because a triangle is the only shape that can't be pushed out of shape without bending a side — it's rigid.
✅ Quick check: Two triangles have three pairs of equal sides. Are they congruent?
Say your answer out loud first — then reveal.
Yes — by SSS (side-side-side), matching all three sides forces congruence.
Three equal sides fix a triangle completely, so the two must be identical.
🧪 Try it! (2 minutes)
Cut two paper triangles with the same three side lengths — they'll stack perfectly, in some flip/turn.