Section 1
Defining a Quadrilateral
Property
A quadrilateral is a polygon with exactly four sides and four vertices.
The sum of all interior angles in any quadrilateral equals :
In this Grade 5 Illustrative Mathematics lesson, students explore the hierarchy of quadrilaterals by examining how categories such as parallelograms, rectangles, rhombuses, and squares relate to and nest within one another. Students use shared attributes to classify shapes and understand why a square, for example, belongs to multiple categories simultaneously. This lesson builds geometric reasoning skills aligned with the properties and classification of two-dimensional figures.
Section 1
Defining a Quadrilateral
A quadrilateral is a polygon with exactly four sides and four vertices.
The sum of all interior angles in any quadrilateral equals :
Section 2
Types of Quadrilaterals
Think of these shapes like a family tree! A square is a special type of rectangle, which is a special type of parallelogram. Each shape inherits traits from the one above it but adds its own unique rule.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter
Expand to review the lesson summary and core properties.
Section 1
Defining a Quadrilateral
A quadrilateral is a polygon with exactly four sides and four vertices.
The sum of all interior angles in any quadrilateral equals :
Section 2
Types of Quadrilaterals
Think of these shapes like a family tree! A square is a special type of rectangle, which is a special type of parallelogram. Each shape inherits traits from the one above it but adds its own unique rule.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter