Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, students must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Curated OER
The Sum of All Angles
Students add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad lesson plan, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons....
EngageNY
Applications of Congruence in Terms of Rigid Motions
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
Curated OER
Quadrilateral Characteristics
Fourth graders explain the characteristics of quadrilaterals and describe, identify and analyze characteristics and properties of geometric shapes.
Houghton Mifflin Harcourt
Introducing the Concept: Triangles and Quadrilaterals
Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...
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
Relationships Among Arc and Angle Measures in Circles
Students follow the directions on the attached worksheet to construct shapes using Geometer's Sketchpad. To start the instructional activity, it is suggested that the teacher guide the students through the initial problem. When...
Curated OER
Patterns and Linear Functions
Students investigate the concept of a linear function. They use geoboards to find the interior angle sums. The sum of the angles is found to equal 180 degrees. Students also investigate quadrilaterals.
Improving Measurement and Geometry in Elementary Schools
Rep Tiles
In addition to the catchy title, this lesson plan provides upper graders an opportunity to more closely scrutinize the attributes of plane figures. In particular, they focus on the similarity of different shapes. Both whole-class and...
Curated OER
Triangles and Things
Young learners listen to the story book The Greedy Triangle as the teacher introduces new polygon shapes. They use geometric stencils to trace a quadrilateral, a pentagon, a hexagon, and an octogon onto a foldable notepad. They identify...
Curated OER
Sphere Dressing
Geometric design makes a fashion statement! Challenge learners to design a hat to fit a Styrofoam model. Specifications are clear and pupils use concepts related to three-dimensional objects including volume of irregular shapes and...
Curated OER
Balancing Act
Second graders identify the attributes of various shapes and estimate the weight of the objects. In this geometry lesson, 2nd graders identify the attributes of concrete objects and use a pan balance to weight them.
Curated OER
Pattern Block Polygons
Sixth graders create polygons. In this shapes lesson, 6th graders explore prefixes such as oct, tri, quad, pent, etc. and share their findings. Students use pattern blocks to create two different polygons and label them.
Curated OER
Unit Perimeters and Areas
Students use Geometers SketchPad to find the area and perimeter of several shapes. In this geometry instructional activity, students determine area of rectangles and progress through irregular polygons. None of the referenced worksheets...