Curated OER
Isosceles Triangles
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
Curated OER
SAS Similarity Theorem
Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
Curated OER
Similar Triangles on the Coordinate Plane
Students investigate triangles and their properties. In this geometry lesson, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or congruent.
Curated OER
Concurrent Lines in Triangles
Students explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson plan, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Students use a...
Curated OER
Geometry: Classifying Quadrilaterals
Young scholars 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
Compass Designs
Students investigate the properties of two and three dimensional objects. In this geometry lesson, students differentiate polygons based on similarity and congruence. They make observation and interpret the data.
Curated OER
What's Your Design?
Sixth grade students: design a stained glass window, submitting their initial plan detailing the measurements of all lines and angles. Seventh grade students: create a scale drawing of their own geometric family of four members.
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson plan, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
Make a Box
Pupils use specific dimensions to create a box. In this geometry lesson, students analyze the different properties of two and three dimensional shapes. They make conjectures and use it to solve problems.
Curated OER
Exploring Arrangements of 2, 3, 4, and 5 Cubes
Learners construct models of various tricubes, tetracubes, and pentacubes that are possible, classify n-cubes into different groupings, and draw these figures on isometric dot paper giving true perspective to what they visualize.
Curated OER
Math: Arcs and Chords
Students draw diagrams demonstrating how it is possible to two central angles to be congruent and their minor arcs are not congruent. In groups, they illustrate theorems with their constructed circles, create diameters of circles that...
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...
Curated OER
Ship Shape
Second graders explore shapes and create a Silly Shape book. Students recognize that shapes have certain properties and be able to define them. Example, a triangle is any three-sided shape. Students' job is to make a picture on...
Curated OER
Tangrams
Students construct the tangram pieces from a square paper by following directions to fold and cut. They make observations on the pieces formed and compare how they are related to each other. They explore patterns and shapes with the...
Inside Mathematics
Quadrilaterals
What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...
Shodor Education Foundation
An Introduction To Quadrilaterals
Young geometers investigate and apply properties of quadrilaterals. After a review and discussion of key terms, students use a computer applet to explore four-sided figures and classify them according to their attributes. The...
Education Development Center
Proof with Parallelogram Vertices
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
Curated OER
Pythagorean Theorem by Graphic Manipulation
There are many different ways to show a proof of the Pythagorean Theorem. Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Curated OER
Tiling the Classroom
Students see how to identify regular polygons, how to slide, turn and flip polygons, and why certain polygons tessellate better than others. Groups create a one foot square design to be used to tile the classroom. Great lesson!
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...
Virginia Department of Education
Inductive and Deductive Reasoning
Introduce pupils to the two types of reasoning, inductive and deductive. Classmates work in pairs or small groups to learn the difference between the two and apply these reasonings to develop valid conclusions.
Curated OER
Exploring Arrangements of 2, 3, 4, and 5 Cubes
Students use problem solving skills to create various models of tricubes, tetracubes, and pentacubes. They classify the cubes into various groupings and identify them as mirror images, regular arrangements, and irregular arrangements....
Curated OER
Shadow Casting
Eighth graders use a meter stick that is placed on a horizontal surface and an object is moved along it so that the shadow length can be measured at different distances from the light source. They solve real-world problems involving...
Curated OER
Transformational Geometry Using the Geometer's Sketchpad
Students complete a webquest on the various types of symmetry. Using a computer, they explore the concepts of transformational geometry and identify points, segments, lines and planes. They experiment with the rotation of a quadrilateral...