Triangles and four sided shapes

What this chapter teaches

Shapes are sorted by their sides and angles. A square is a special rectangle, because it has everything a rectangle needs. Triangles are named by how many sides are equal.

Three questions to ask

There is no one right wording. Listen for the idea.

1. Is a square a rectangle? What would you say to convince someone?
2. How can you tell a rhombus from a square?
3. What do you look for to decide if a triangle is equilateral, isosceles or scalene?

After the chapter, the learner can

• Name a square, rectangle, rhombus, parallelogram and trapezium
• Sort four sided shapes by their sides and angles
• Sort triangles by how many sides are equal