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...
Virginia Department of Education
Properties of Quadrilaterals
What type of quadrilateral is that? Discover the difference between the types of quadrilaterals. Small groups investigate types of quadrilaterals using geometry software to find their properties. To keep track of the different...
EngageNY
Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
Curated OER
Quadrilateral Attributes
Students classify quadrilaterals. In this quadrilateral lesson, students identify the characteristics of quadrilaterals. They write their findings in a journal. Students use geoboards to create quadrilaterals from given descriptions.
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate the number of...
Curated OER
Diagonals of Quadrilaterals
Teach your mathematicians how to identify different polygons based on their diagonals. Relating quadrilaterals to the different number of diagonals formed, high schoolers use the TI to create a visual of their shape.
Curated OER
Intro To Quadrilaterals
Students engage in a lesson that is concerned with the concept of quadrilaterals and how they are used to create a rectangle for a door. They create a drawing of a quadrilateral while finding the sum of the angles. They practice problems...
Curated OER
World of Quadrilaterals
Students define the importance of the properties of quadrilaterals. In this quadrilaterals lesson, students identify the general properties of and compare and contrast the properties of convex and concave quadrilaterals. Students also...
Curated OER
Symmetries in Quadrilateral Tilings
Students analyze symmetries of quadrilateral tilings and discover how various types of symmetries, used alone or in combination, can generate the same pattern in more than one way.
Curated OER
Polygons and Diagonals
Students practice measuring the interior angles of given regular polygons and create a formula for finding the measure of th interior angles of any polygon. They determine the relationships between the number of vertices's or sides in a...
Curated OER
Developing Formulas for Triangles and Quadrilaterals
In this geometry worksheet, 10th graders determine the area of triangles, parallelograms, trapezoids, kites, and rhombuses. The one page worksheet contains eleven problems. Answers are included.
Curated OER
Diagonals of Quadrilaterals
Students find the diagonals of the quadrilaterals. For this geometry lesson, students identify and use properties of quadrilaterals. They define different parts of a quadrilateral shape.
Curated OER
Quadrilateral Bunny
Young scholars identify the properties representing quadrilateral. In this geometry lesson, students differentiate between special and regular quadrilaterals. They discuss and demonstrate hierarchy of quadrilaterals.
Curated OER
Investigating Area Relationships
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.
Curated OER
Going out of Business: Pythagorean Theorem
Students find the length of diagonals. In this Pythagorean theorem lesson, students use the Pythagorean theorem to determine the length of diagonals.
Curated OER
Properties of Parallelograms
High schoolers discover properties of parallelograms as they construct a parallelogram using Cabri Jr. They will measure angles and side lengths of their construction and determine the relationship between the diagonals of a...
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Mathematics Assessment Project
Evaluating Statements About Length and Area
Class members complete an assessment task by identifying whether statements about triangles and quadrilaterals are always true, sometimes true, or never true. They then participate in a sorting activity with the same objective.
Curated OER
Diagonals to Quadrilaterals II
Students identify the properties of different polygons. In this geometry lesson, students find the slope of a line and calculate the distance between two lines. They differentiate between similar and congruent polygons.
Curated OER
A Rectangle in the Coordinate Plane
A quadrilateral is drawn on the coordinate plane, and eighth grade geometers find the length of each side and the diagonals by applying the Pythagorean theorem.
Curated OER
Area of Polygons
In this area of polygons worksheet, 10th graders solve and complete 12 various types of problems. First, they find the area of a given square. Then, students find the length of an original square as illustrated. They also write an...
Curated OER
Junior Architects of America
Students create entries for the Architects of America contest, including a model of a futuristic structure, blueprints, a list of all plane and solid shapes in the structure, a persuasive argument paper that describes why the structure...
Curated OER
Properties of Parallelograms
Scholars explore parallelograms in this geometry lesson. They investigate the properties of a parallelogram. Assisted by technology, your learners will construct a parallelogram and examine the sides, angles, and diagonals to discover...