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
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
Angle Bisectors and Medians of Quadrilaterals
Young scholars investigate the properties of quadrilaterals formed by angle bisectors of a given quadrilateral and quadrilaterals formed by the medians of quadrilaterals. This Cabri Jr. lesson provides opportunity for conjecture and...
Curated OER
The Trapping of Trapezoids
This is a nice hands-on activity where young geometers create trapezoids and calculate their area by looking at areas of quadrilaterals and triangles.
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...
Concord Consortium
Divisions
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
Curated OER
Inscribed Quadrilaterals and Parallelograms
Learners differentiate between inscribed quadrilaterals and parallelograms. In this geometry lesson, students identify the shaped of the polygons when it is inscribed inside of a circle. They calculate the missing angles of the inscribed...
Curated OER
Lines In Geometry
Students define important vocabulary words using a dictionary. In this geometry lesson, students identify and use properties of triangles to solve problems. They identify the median. altitude and angles as well as properties of...
Curated OER
Geometry: Classifying Quadrilaterals
Learners use construction technology to identify and find relationships between the attributes of various quadrilaterals. They make and test conjectures about the distinguishing properties of parallelograms, rectangles, rhombuses,...
Curated OER
Creating a Midpoint Quad
Using a TI Navigator to drag quadrilaterals around to create different shapes, students learn how to draw midpoints in their quadrilaterals. In this geometry lesson, students solve problems using the properties of quadrilaterals.
Curated OER
Internet Field Trip on Fractions and Geometry
Students take an Internet field trip to research fractions. ESOL strategies include using pattern block manipulatives and pairing ESOL and non-ESOL students on computers.
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...
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...
Curated OER
Side Length, Perimeter, and Area of a Rectangle
Learners calculate area, perimeter and length of rectangles. In this geometry lesson, students create different formulas for the problem they are being asked to solve. They use the navigator to move the shape around and make observations.
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...
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. Students are asked to divide the...
Curated OER
2-D Geometry
Third graders are introduced to new vocabulary related to Geometry. As each word is mentioned, they demonstrate the word with their body. In groups, they identify the similarities and differences between each line and angle. To end...
Curated OER
Tricky Traps
Students create identify properties of trapezoids. For this geometry lesson, students calculate the area of given trapezoids and review the area formula for parallelograms. They draw a correlation between the area of a trapezoid and that...
Curated OER
Robot Area
Students calculate the area of different polygons. In this geometry instructional activity, students explore polygons based in their shape and number of sides. They find the formula for the area and use each specific formula for each shape.
Texas Instruments
Trisecting a Square
High Schoolers investigate the question of whether or not the area of square can be trisected. In this lesson, they use geometry software to answer the questions and determine what conditions are necessary to the three regions to by equal.
Curated OER
Similarity and Dilations - Discover Properties of Similar Figures
Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...
Math Solutions
Shape Sorting: Looking for Green!
Young mathematicians rotate, flip, and sort their way to an understanding of the different attributes of geometric figures. Using transparent yellow and blue shapes, children try to match congruent figures together to create...
Education Development Center
Finding Parallelogram Vertices
Four is the perfect number—if you're talking about parallelograms. Scholars determine a possible fourth vertex of a parallelogram in the coordinate plane given the coordinates of three vertices. They read a conversation...