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Worksheet
Curated OER

Similar Triangles and Trapezoids, and Circles

For Students 9th - 12th
High schoolers answer two problems involving area of shaded regions. Students then answers six questions involving perimeter, area, and circumferences. The remaining two questions involve ratios of similar figures.
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Lesson Plan
Mathematics Assessment Project

Identifying Similar Triangles

For Teachers 7th - 9th Standards
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...
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Worksheet
Curated OER

Kuta Software - Infinite Geometry: Similar Triangles

For Students 9th - 12th
For this similar triangles worksheet, students solve 20 short answer problems. Students determine if two given triangles are similar.  Students determine the type of similarity given two triangles. Students are given a sketch of the...
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Lesson Plan
Virginia Department of Education

Similar Triangles

For Teachers 9th - 11th Standards
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
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Activity
Education Development Center

Similar Triangles

For Students 8th - 10th Standards
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.
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Worksheet
Curated OER

Chapter 8 Extra Problems Worksheet: Similar Triangles

For Students 9th - 12th
In this similar triangles activity, students solve 6 similar triangles. Students use proportions to solve similar triangles and similar rectangles.
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Worksheet
Curated OER

A Geometry Worksheet - Similar Triangles

For Students 9th - 12th Standards
In this similar triangles worksheet, students find the scale factor of 6 sets of similar triangles. Students find the scale factor of two similar triangles given a sketch with measurements. Students use proportions to find a missing side...
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Lesson Plan
EngageNY

Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams

For Teachers 9th - 12th Standards
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...
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Worksheet
Curated OER

Identify Similar Triangles With Proofs

For Students 10th - 12th
In this similar triangle worksheet, students write a two-column proof to explain why determined triangles are similar. Given some line lengths and angle measurements, students use proofs to identify the ratio of specified angles. This...
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Worksheet
Lane Community College

Review Sheets: Geometry

For Students 8th - 11th
Full of problems with polygons, angles, lines, and triangles, your learners get a multi-page packet that provides all they need to know. It contains many of the standard problem types as well as some more challenging questions. 
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Worksheet
Curated OER

Circles: Geometry Review Worksheet

For Students 10th Standards
Tenth graders solve and complete 14 different geometry problems. First, they find the area and circumference of a circle with a given radius. Then, they find the area between a circle and an inscribed equilateral triangle given the...
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Worksheet
Curated OER

Similar Triangles

For Students 10th
In this similar triangles worksheet, 10th graders solve and complete 10 different problems related to determining the sides of similar triangles. First, they write three equal ratios to show the corresponding sides that are proportional....
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Worksheet
Curated OER

Dilations and Similarity

For Students 8th - 10th Standards
In this dilations and similarity instructional activity, pupils solve 10 different problems that include various dilations. First, they determine the scale factor of dilations found in the illustrated graphs. Then, everyone determines...
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Lesson Plan
Willow Tree

Ratios and Proportions with Congruent and Similar Polygons

For Students 8th - 11th Standards
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
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Assessment
Inside Mathematics

Rhombuses

For Teachers 9th - 12th Standards
Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...
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Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
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...
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Lesson Plan
Virginia Department of Education

Special Right Triangles and Right Triangle Trigonometry

For Teachers 9th - 11th Standards
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
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Assessment
Illustrative Mathematics

Coordinates of Equilateral Triangles

For Students 9th - 12th Standards
Can it be constructed? The task poses the question whether it is possible to have an equilateral triangle with its vertices located at integer coordinates. Pupils work with their knowledge of trigonometric ratios and the Pythagorean...
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Worksheet
Curated OER

Similar Figures

For Students 10th
In this geometry worksheet students explore similar polygons and determine measure of missing sides and angles. Students use indirect measurement with similar triangles and determine the area and volume of similar figures. The seven page...
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Assessment
Mathematics Assessment Project

Hopewell Geometry

For Students 8th - 10th Standards
Right triangles from 2,000 years ago? Learners investigate different right triangles found in the earthworks of the Hopewell people, a Native American culture that populated the United States from 200BC to AD 500. Learners apply concepts...
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Activity
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Curated OER

Mt. Whitney to Death Valley

For Teachers 9th - 12th Standards
This is an intriguing problem that brings together real-world data, technology, and mathematical problem solving. If visibility wasn't an issue, could you see from the highest point in the lower 48 states, Mt. Whitney, to the lowest...
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Worksheet
Curated OER

Triangle Similarity

For Students 10th
In this triangle similarity learning exercise, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...
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Activity
Curated OER

Unit Squares and Triangles

For Teachers 9th - 11th Standards
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
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Lesson Plan
Curated OER

Review Geometry - Week 8 (Triangles)

For Teachers 11th - 12th
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.