Education Development Center
Similar Triangles
Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.
Curated OER
Countdown Challenge: Similarity
In this similarity worksheet, students use similar rectangles to find the length of a diagonal. They use symbols and write paragraphs to explain the problem. This one-page worksheet contains one similar problem with 13 related questions.
Curated OER
Countdown Challenge: Similarity
For this similarity worksheet, students observe similar rectangles and determine the length of the diagonal. They use words, symbols and diagrams to solve the problem and explain the results. This one-page worksheet contains one...
El Paso Community College
Geometry Definitions
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet.
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
Curated OER
Ratio of Similarity
In this ratio of similarity worksheet, 10th graders solve and complete 20 different problems that include defining the ratio of similarity in various figures. First, they determine the ratio of similarity for large and small pairs of...
EngageNY
Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
EngageNY
End-of-Module Assessment Task - Geometry (module 2)
Increase the level of assessment rigor with the test of performance tasks. Topics include similar triangles, trigonometric ratios, Law of Sines, Law of Cosines, and trigonometric problem solving.
EngageNY
Incredibly Useful Ratios
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent sides before exploring...
Georgia Department of Education
Analytic Geometry Study Guide
Are you looking for a comprehensive review that addresses the Common Core standards for geometry? This is it! Instruction and practice problems built specifically for standards are included. The material includes geometry topics from...
Virginia Department of Education
Transformations
The coordinate plane is a popular place! Identify rotations, reflections, and dilations on the coordinate plane. Pupils work in small groups to match transformations of a figure with the description of the transformation. They perform...
Curated OER
Similar Situations
Students explore intersecting lines. In this intersecting lines lesson, students investigate shapes consisting of parallel, perpendicular, and similar lines. Students investigate these lines in shapes around them.
Inside Mathematics
Hopewell Geometry
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
EngageNY
Properties of Similarity Transformations
You can explain it, but can you do it? After learners view a sequence of transformations, the next logical step is creating the transformation. Challenge your classes to construct a composition of transformations and verify the...
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles.
Virginia Department of Education
Similar Figures
How similar do figures have to be to be similar figures? Individuals learn to identify similar figures by verifying that angles are congruent and sides are proportional. Additionally, they match the corresponding parts of similar figures.
CK-12 Foundation
Midpoint and Segment Bisectors: Finding Treasure with Geometry
Send your class on the hunt for a buried treasure and apply geometry skills along the way. An engaging lesson uses direction and midpoint locations to find the location of a treasure. Videos provide background information to complete the...
EngageNY
Mid-Module Assessment Task - Geometry (Module 1)
How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...
West Contra Costa Unified School District
Expository Writing in Math
Pupils engage in an activity where one partner reads directions while the other follows those directions to complete a math task (such as bisecting an angle). As a reflection, they examine products to see what information the best...
CK-12 Foundation
Polynomials in Standard Form
Set the standard for working with polynomials. Pupils arrange two polynomial expressions in standard form. The scholars respond to questions about the terms, coefficients, and degrees of the polynomials. They then discuss how they can...
CK-12 Foundation
Applications of Linear Systems: Alcohol Solution in Nursing
Solve alcohol systems to find the right solution. The interactive allows pupils to manipulate the amount of a solution and displays the total amount in a mixture. Individuals determine the amount of each solution needed to make 15 liters...
CK-12 Foundation
Seasonal Changes in Plants: Leaf Pigment
Leaves fall off the tree in the autumn, but why do they change colors? The interactive covers the role of chlorophyll and photosynthesis. It also explains both carotenoids and anthocyanins.
CK-12 Foundation
Ordered Pairs in Four Quadrants
One quadrant just isn't enough. Pupils learn to plot points in the four quadrants of a coordinate plane using an interactive. A set of challenge questions tests their understanding of the skill.
CK-12 Foundation
Points in the Coordinate Plane
Map your way to success in understanding coordinate points. Individuals drag town landmarks to their appropriate locations on a coordinate plane representing a map. They answer a set of challenge questions to see if their answers are...