Illustrative Mathematics
What is a Trapezoid? (Part 1)
Challenge your class to construct a definition for trapezoids. Looking at four examples and four non-examples, students individually create definitions and use them to classify an unknown shape. Allow for small group and whole-class...
Illustrative Mathematics
Lines of Symmetry for Quadrilaterals
Explore how lines of symmetry help define different categories of quadrilaterals. Looking at a square, rectangle, trapezoid, and parallelogram, young mathematicians discover that each shape has its own, unique symmetry. Encourage your...
Curated OER
Quadrilaterals: 2 dimensional shapes with 4 straight sides
Which shapes are considered quadrilaterals? View and learn that two dimensional shapes with four straight sides are considered quadrilateral. The rhombus, parallelogram, rectangle, and trapezium are only few of the fabulous shapes shown...