Curated OER
Exploring Polygons and The Greedy Triangle
Excellent instructional activity! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump...
EngageNY
Perimeter and Area of Polygonal Regions in the Cartesian Plane
How many sides does that polygon have? Building directly from lesson number eight in this series, learners now find the area and perimeter of any polygon on the coordinate plane. They decompose the polygons into triangles and use Green's...
Curated OER
Identify Polygons: Algebra/Geometry Institute
Eighth graders classify geometric figures. In this polygon lesson, 8th graders identify given geometric figures. They compare and contrast different polygons. Students name line segments, identify parallel lines, and...
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.
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Young scholars are asked to divide the...
Curated OER
An Introduction to Quadrilaterals
High schoolers explore the concept of quadrilaterals. In this quadrilateral lesson, students play with a floor tile applet to see that there are many types and characteristics of quadrilaterals including parallelograms, trapezoids,...
Curated OER
Areas of Polygons
Young mathematicians calculate the area of polygons in this algebra lesson. They find the determinant as they calculate the areas for triangles and quadrilaterals. They also use scalar multiplication to find the determinant.
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, students use the TI to create a visual of their shape.
Curated OER
Properties of Special Quadrilaterals
Teach your mathematicians how to identify the properties of quadrilaterals. In this geometry lesson plan, students solve for missing angles and sides of a special quadrilateral. They use the TI to move the sides around and create...
Curated OER
Sum of Exterior Angles of Polygons
Have fun calculating angles for different polygons. The class differentiate the relationship between the interior and exterior angles of polygons. They discuss linear pair as it related the polygons and their angles. This is done as they...
EngageNY
Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities
When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...
Curated OER
An Introduction to Quadrilaterals
Students explore different types of quadrilaterals. Students define the terminology used with quadrilaterals. They create particular quadrilaterals based on specific characteristics of the quadrilaterals using an online tool.
Curated OER
Problem Solving Using Power Polygons
Students investigate geometric shapes by creating figures on a plane. In this polygon lesson, students complete a worksheet based on the angles in a power polygon. Students identify the different types of polygons and define their...
Texas Instruments
Construction Regular Polygons
Learners investigate the process necessary to construct regular polygons. They explore the degree measures of the angles in a regular polygon. Using this information and technology in the form of Cabri Jr., your pupils will construct...
Illustrative Mathematics
What is a Trapezoid? (Part 2)
This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...
Curated OER
Interior and Exterior Angles of Polygons
Students identify interior and exterior angles of polygons. For this geometry lesson, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.
Curated OER
Quadrilateral within Quadrilaterals
Students investigate the properties of quadrilaterals. In this geometry activity, students solve problems dealing with construction and designs. They work with quadrilaterals, midpoints and parallelograms.
Curated OER
Diagonals to Quadrilaterals II
Pupils 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
Patterns in the Sums of Polygon Angles
Sixth graders discover the patterns of sums of polygon angles. In this math lesson, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.
Curated OER
Areas of Trapezoids, Rhombuses and Kites
Students calculate the area of different polygons. For this geometry lesson, students find the area for trapezoids, rhombuses and kites.
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
IGD: Perpendicular Bisector
High schoolers draw perpendicular bisectors. In this perpendicular bisectors lesson, students identify the perpendicular bisector in a polygon. They use web tools to create and measure perpendicular bisectors. High...
Curated OER
Meet the Polygon Family
Fourth graders investigate regular polygons. In this regular polygon activity, 4th graders explore the attributes of different polygons. Students work in groups to complete a KWL chart regarding polygons.
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.