Curated OER
Diagonals to Quadrilaterals II
Students identify the properties of different polygons. In this geometry lesson plan, students find the slope of a line and calculate the distance between two lines. They differentiate between similar and congruent polygons.
Curated OER
Tangents to a Circle
Young scholars construct tangent lines. In this geometry lesson, students identify the point of tangency, secant and tangent lines. They graph the lines on the Ti and make observations.
Curated OER
Geometry of Triangles - Week 6
In this geometry of triangles worksheet, learners find the length of sides, are, and angle measurement of inscribed triangles, pentagons, and midpoint of a line. This two-page worksheet contains seven problems.
Curated OER
SAS Similarity Theorem
Students identify and use the similarity theorem. In this geometry instructional activity, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
Curated OER
Intro to Geometry
Seventh graders identify a polygon and classify them using congruent sides and number of edges and vertices. Students transform two dimensional objects into three dimensional objects.
Curated OER
SuperShapes, Part 1; "Tri"ing Triangles
An outstanding instructional activity on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about...
Curated OER
Marshmallow Geometry
In this three-dimensional shapes geometry lesson, learners identify geometric solids and name their properties. They define "face," "edge," and "vertex," and construct geometric solids using marshmallows as vertices and toothpicks as edges.
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.
Willow Tree
Angle Sum Property of Triangles
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.
EngageNY
Complex Numbers as Vectors
Show your math class how to use vectors in adding complex numbers. Vectors represent complex numbers as opposed to points in the coordinate plane. The class uses the geometric representation to add and subtract complex numbers and...
EngageNY
Circles, Chords, Diameters, and Their Relationships
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
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 activity!
Curated OER
3-D Cubes
Pupils investigate cubes. In this geometric solids lesson, students review geometric concepts previously taught, then logon to a computer game in which they find cube figures and identify the shadow of hidden cubes.
Curated OER
Angle Exploration and Classification
Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.
Curated OER
Pass it On
Young scholars participate in a class activity to help them master geometric terms and their definitions.
Curated OER
What Shape am I?
Students analyze characteristics of geometric shapes. They find shapes in their environment, and communicate why it is like the shape of their choice and not like another shape.
Curated OER
What Shape Am I?
First graders analyze characteristics of geometric shapes. They identify, describe, and create simple geometric figures. They analyze characteristics of geometric shapes and determine the defining attributes of a circle,...
Curated OER
Shapes Are Everywhere
Third graders use various shapes to identify polygons and understand symmetry. They explore pattern blocks noticing their similarities and differences, then share with other team members. They draw 3 polygons in their journals and...
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.
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
Utah Education Network (UEN)
Finding Missing Lengths of Similar Triangles
Middle and high schoolers explore the properties of similar triangles. In this geometry lesson, pupils play a similarity basketball game, sketch similar triangles, and find the missing measures of similar figures. They find the height of...
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...
Curated OER
Constructions of Isosceles and Equilateral Triangles
Pupils explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each student has to...