Curated OER
Triangle Attributes and Measures
Seventh graders explore the concept of triangles. In this triangles lesson, 7th graders sort triangles according to various attributes such as acute, obtuse, isosceles, or equilateral. Students find the area and perimeter of triangles.
West Contra Costa Unified School District
Congruent and Similar Polygons
What's similar about congruent and similar polygons? Young mathematicians first measure the side lengths and angles of given figures. They use these measurements to determine relationships between side lengths and angles of congruent and...
Curated OER
Geometry in the Real World
Eighth graders complete a unit of lessons on basic geometry concepts. They participate in a variety of activities, culminating in a project that involves publishing a booklet or a poster that presents the major geometry concepts from the...
Curated OER
Introduction to Fractals: Infinity, Self-Similarity and Recursion.
This lesson introduces students to the ideas involved in understanding fractals. They develop a sense of infinity, self-similarity and recursion and
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...
Curated OER
Basic Geometric Constructions
Pupils observe and demonstrate a variety of basic geometric constructions using the Triman Safety Compass. Using the compass, they draw circles, bisect a line segment, construct an angle, bisect an angle, copy an angle, and create...
Curated OER
Fashion Day
Eighth graders practice using basic measurements to solve word problems.They also investigate finding the perimeter of different polygons and define the characteristics to classify the shape as a polygon.
Curated OER
Investigating the properties of a circle
Young scholars use wax paper to look at different properties of circles such as chords, tangent lines, inscribed angles, and inscribed angles in a semi-circle, as well as finding the center of the circle, and use GSP to investigate...
Curated OER
Are you in Golden Shape
Students solve and verify the solution for unknown measures. In this geometry lesson plan, students identify the properties of circles. They use the arc, angle and segment relationship to find the missing measures.
Curated OER
Triangle Inequality Theorems Investigation
Students estimate and measure triangles. In this geometry lesson, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.
Curated OER
Exploring Special Segments in Triangles
Students discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.
Curated OER
Got Complements? with Cabri Jr.
Learners use the axes and measure angle tool to explore and calculate complementary angles with Cabri Jr. They also identify what happens to the calculation as they drag the endpoint into a different quadrant. Finally, they label each...
Curated OER
Triangle Puzzler
Students are introduced to some basic concepts of geometry. They explain that the definition of a triangle is a figure with three sides, three angles, and three points. Triangles can be named by using three points in their correct sequence.
Curated OER
Perimeter All Around
Students explore perimeter and area of regular and irregular polygons. They experiment with color squares and create different arrangements using the same number squares. Then they compare the area and perimeter measurements of each.
Curated OER
Geometry, Measurement & Reasoning
Students complete worksheets involving rotational symmetry. In this geometry lesson plan, students complete worksheets to identify rotational symmetry and rotations. They compare and contrast rotated figures. Students examine the...
Curated OER
Tangent Properties
Students explore properties of tangent lines. In this properties of tangent lines lesson, students discuss the perpendicular relationship between a tangent line on a circle and the circle's radius. Students use that relationship to...
Curated OER
Identify Similar Figures
Learners explore the concept of similar figures. For this similar figures lesson, students develop the idea that similar figures are a different size but the same shape by comparing similar rectangles. Learners use patty paper to trace...
Curated OER
Betweenness and the Sum of Parts
High schoolers differentiate lines and angles using betweenness in this geometry lesson. They differentiate angles and lines using Cabri Jr. and analyze the data and make conjecture.
Key Curriculum Press
Triangle Inequalities
Properties about triangles are explored in this lesson. Geometers make conjectures about the length of a triangle's sides, the length of the angles in relation to the length of the sides, and the measure of the exterior angles of a...
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
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.
EngageNY
Reflections
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
Curated OER
Up For Change?
Students explore similar objects. They participate in a series of hands-on, multimedia and online activities to examine how the edge length affects the angle measures, perimeters and areas of similar regular polygons. Students find the...
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.