Grade 2 Math Book · Shapes & Geometry
The Greedy Triangle
by Marilyn Burns
A triangle gets bored and asks the shapeshifter for one more side, becoming a quadrilateral, then a pentagon, a hexagon and more. But the more sides it gets, the less happy it is.
Why it's useful
A funny story that teaches shape names and properties.
- Sides and angles. Each new shape has one more side and one more angle.
- Shapes in the real world. The triangle finds where each shape shows up in daily life.
- Shape vocabulary. Quadrilateral, pentagon, hexagon and more become familiar.
Try it in class or at home
- Geoboard shapes. Make the triangle, then add one side at a time.
- Shape hunt. Find each shape around the school.
- Count it. Make a table of shape names with number of sides and angles.