Curated OER
Finding the Area of an Equilateral Triangle
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
Curated OER
Exploring Geometric Mean
Student identify the solution using geometric mean. In this geometry lesson, students create right triangles where the altitude of the triangle is the side containing the right angle. They modify shapes using Cabri software and observe...
Willow Tree
Perimeter of Common Geometric Figures
Help learners understand that perimeter and circumference are one in the same. Learners apply their skills to determine the perimeter/circumference of triangles, rectangles, and circles. They then use the same strategy to find the...
Illustrative Mathematics
Placing a Fire Hydrant
Triangle centers and the segments that create them easily become an exercise in memorization, without the help of engaging applications like this lesson. Here the class investigates the measure of center that is equidistant to the three...
Curated OER
Investigation - Looking For Triangles
Seventh graders investigate a series of triangles, looking for patterns and generalizing what they have found. They analyze the pattern data and organize it into a table and graph. Students identify the relationship and discover the rule...
Curated OER
Exploring Geometric Mean
Students solve problems using geometric means. In this geometry lesson plan, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.
Curated OER
Can a Geometric Mean be Nice?
For this Geometry instructional (work)sheet, students are instructed on how to find the geometric mean. Students are then shown how the geometric mean is applied to proving similar triangles.
Curated OER
The Geometry of Means
For this geometry worksheet, students are given a rectangle and a square. They verify ratios when given equal perimeters or areas. Students are given adjacent squares. They find the distance between the centers, and identify the means...
Curated OER
Discovering Art-Huntington Gallery Shape
Students study geometric, naturalistic, and abstract shapes. They discuss how various shapes are used in art. They study The Young Fortune Teller by Joshua Reynolds to find various shapes.
Willow Tree
Area of Common Geometric Figures
Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
Virginia Department of Education
Pythagorean Theorem
Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.
Curated OER
Angles, Triangles, Quadrilaterals, Circles and Related
Students classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
Curated OER
Naming Shapes
Students study geometric shapes and practice naming them properly. In this geometry lesson, students work in groups to give definitions of the vocabulary to each other in their own words. Students also visit a lower grade and teach...
Curated OER
Introducing Powers and Models
Learners construct two dimensional models to illustrate squared numbers. In this geometry lesson, students use graph paper and an x/y axis to build squares exponentially. Learners identify powers and relationships between various figures...
Curated OER
Using Geometric Shapes To Make Patterns
Sixth graders explore the use of shapes to create geometric patterns. they start with a simple example of dividing shapes in half to create two new ones. This can be extended to creating intricate patterns.
Curated OER
What's in a Shape?
Students explore characteristics of shapes by making and using tangram sets. They discover how the tangram pieces are related to one another, and determine how many different combinations of the triangles, squares, and parallelograms in...
EngageNY
From Circle-ometry to Trigonometry
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
EngageNY
Why Call It Tangent?
Discover the relationship between tangent lines and the tangent function. Class members develop the idea of the tangent function using the unit circle. They create tables of values and explore the domain, range, and end behavior of...
Pennsylvania Department of Education
Making Triangles
Students use interactive geoboards to identify simple geometric shapes. In this making triangles lesson, students describe the properties associated with geometric shapes. Students develop spatial sense and the mathematical meaning...
Curated OER
Geometry and Quilting
Fourth graders combine geometry and language arts skills while examining quilt-making. After identifying the geometric shapes contained in quilts, they write stories to encompass the quilt border. Students conclude by creating and...
Curated OER
Central Valley Math Project
Middle schoolers study the Pythagorean Theorem. They describe what it means to square a number. Pupilsuse the Pythagorean Theorem to prove the sides of given triangles, and use geometric pieces of paper to create a right triangle and...
EngageNY
Law of Cosines
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
Virginia Department of Education
Side to Side
Congruent figures: two figures that want to be just like each other. Individuals learn to distinguish between figures that are congruent and those that are not. Measuring the lengths of line segments and angles helps in this endeavor.
Curated OER
Inked Geometric Mandalas
Fifth graders gain an appreciation for mandalas in many cultures. Compare and contrast designs from many cultures. They see geometric design in mandalas and become aware of symmetrical balance and radial balance. They create a mandala...