Yellow
Green
Blue
Red
Magenta
Remove
Two shapes are congruent if they have the same size and shape. You can show that one shape is congruent to another by moving it so that it covers the other shape exactly. You may need to flip it.
- Cover one shape below using the two small triangles from the tangrams. Show that it is congruent to the second shape by turning it to cover the second shape.
Rules for Building with Triangles
Use these rules for building shapes with triangles:
Rule 1. Edge-to-edge rule: The triangles must be put together edge to edge.
Rule 2. Same-shape rule: Count two shapes as the same if they are congruent.