Classify triangles, quadrilaterals and other polygons according to their side...

Quick preparation

• classify triangles, quadrilaterals and other polygons according to their side and angle properties; identify and reason about relationships
• using strips of paper with parallel sides to make triangles and quadrilaterals, and contrasting the rigidity of triangles with the flexibility of…
• constructing triangles with 3 given side lengths and discussing the question, “Can any 3 lengths be used to form the sides of a triangle?”