Curated OER
The Pythagorean Theorem Lesson 2
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
Curated OER
Triangles Inscribed in a Circle
Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra. Learners are...
Curated OER
Review Geometry - Week 8 (Triangles)
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.
Inside Mathematics
Rhombuses
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...
Curated OER
Unit Squares and Triangles
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...
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.
CK-12 Foundation
Reference Angles and Angles in the Unit Circle: Exploring Reference Angles
A steal of a deal — get four angles for the value of one. An interactive resource allows individuals to visualize all four angles that have the same reference angle. Pupils answer questions by using the interactive to create the...
CK-12 Foundation
Pythagorean Theorem to Determine Distance: Distance Between Friends
Pupils use an interactive to help visualize the right triangles needed to calculate distances between friends' houses. Individuals solve five problems on how to determine distances and comparing the distances.
Flipped Math
Intro to Trigonometry
Expand trigonometric ratios beyond right triangles. Pupils start with a review of trigonometric ratios and then take a look at angles in standard position to determine their measurements. Scholars discover how to find coterminal angles...
Curated OER
Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
CK-12 Foundation
Unit Circle: Medieval Castle Defense
Who needs a plan — let trigonometry protect you! Pupils determine the angle of an approaching enemy to a village wall. The scholars determine the exact value of trigonometric functions for the angle. Class members use trigonometry to...
Curated OER
Similar Polygons
In this similar polygons worksheet, 10th graders solve and complete 20 various types of problems. First, they solve each proportion. Then, students write a ratio expressing the slope of a line through each pair of points. In addition,...
Curated OER
Angles ~ Right Angles
Have your class review how to identify right angles. Learners identify right angles, and then write the number of angles found in each shape.
Curated OER
Pythagorean Theorem
Young scholars are introduced to the Pythagorean theorem. They use three different activities that give students the opportuntiy to observe triangles, and use the Pythagorean theorem and practice different ways of determining areas of...
Curated OER
Mt. Whitney to Death Valley
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...
Curated OER
Corresponding Parts of Similar Triangles
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...
Curated OER
Angles and Similarity
High schoolers identify triangles as similar or congruent. In this geometry lesson, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Curated OER
Ratios of Similar Figures
Students identify the ratios of different triangles. In this geometry lesson, students identify the similarity and differences of triangles. They use the navigator to move the sides of the triangle around.
Curated OER
Triangle Congruence
Students use web applet to create congruent triangles. In this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
Curated OER
Congruent Triangles
Students identify properties of triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the umber of sides to help define the angle of the polygon.
Curated OER
Similar Triangles
Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.
Curated OER
Similar Triangles - Applied Problems
Students differentiate between similar and congruent triangles. In this geometry lesson, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
Houghton Mifflin Harcourt
Similar Polygons and Circles
In these similar polygons and circles worksheets, students complete 15 questions including 9 word problems regarding similar polygons. Students then complete 15 questions including 1 word problem involving circumference, area, and arc...
Curated OER
Analyzing Congruence Proofs
Looking at numerous examples of triangles, each with different properties, geometers develop their understanding of congruency. They use the notation of a counter-example to disprove certain conjectures and prove geometric theorems and...