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Lesson Plan
West Contra Costa Unified School District

Investigating Similar Triangles

For Teachers 9th - 12th
Let your use of the resource be in proportion to its usefulness. Pupils investigate similar triangles by measuring side lengths and considering given angle measures. The results of the investigation help develop generalizations about...
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Lesson Plan
Utah Education Network (UEN)

Finding Missing Lengths of Similar Triangles

For Teachers 7th - 10th
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...
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Lesson Plan
Utah Education Network (UEN)

Finding Slope of a Line from Graphs, Tables, and Ordered Pairs

For Teachers 7th - 9th Standards
Middle schoolers explore the concept of slope in numerous ways and start to look at simple linear equations. They describe the slope in a variety of ways such as the steepness of a line, developing a ratio, using graphs, using similar...
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Lesson Plan
EngageNY

The Side-Angle-Side (SAS) and Side-Side-Side (SSS) Criteria for Two Triangles to Be Similar

For Students 9th - 10th Standards
Playing with mathematics can invoke curiosity and excitement. As pupils construct triangles with given criteria, they determine the necessary requirements to support similarity. After determining the criteria, they practice verifying...
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Lesson Plan
Curated OER

Exploring Polygons and The Greedy Triangle

For Teachers 1st - 3rd
Excellent lesson! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes), partners form the various shapes...
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Lesson Plan
Curated OER

When Does SSA Work to Determine Triangle Congruence?

For Teachers 9th - 10th Standards
Your learners will make good use of the Socratic method in a collaborative task that begins with an assumed solution and ends with deeper understanding of the idea of determining two triangles congruent.
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Lesson Plan
Curated OER

Similar Figures

For Teachers 9th - 12th Standards
Your class will use a TI calculator to drag vertices of rectangles and triangles to observe what happens to ratios of pairs of sides within each figure. They will apply the definition of similarity to identify similar shapes. The...
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Lesson Plan
Curated OER

Similar triangles

For Teachers 10th
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
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Lesson Plan
Curated OER

Triangles Inscribed in a Circle

For Teachers 9th - 12th Standards
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...
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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

Angles and Similarity

For Teachers 9th - 12th Standards
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...
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Lesson Plan
Curated OER

Triangle Congruence

For Teachers 9th - 11th
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.
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Lesson Plan
Curated OER

Congruent Triangles

For Teachers 9th - 12th Standards
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.
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Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles

For Teachers 9th - 10th
Students identify similar and congruent right triangles. In this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
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Lesson Plan
Curated OER

Analyzing Congruence Proofs

For Teachers 9th - 12th Standards
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...
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Lesson Plan
Curated OER

Constructing Midsegments of Triangles

For Teachers 9th - 10th
Learners construct midsegments. In this geometry instructional activity, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
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Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles.

For Teachers 8th - 10th
49Students investigate the properties of right triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
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Lesson Plan
Curated OER

Why can't We Use SSA to Prove Triangles Congruent?

For Teachers 9th - 10th
Students investigate triangles and congruences. In this geometry instructional activity, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
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Lesson Plan
Curated OER

Pedal Triangles

For Teachers 8th - 10th
Students identify the properties and theorems of triangles. In this geometry lesson plan, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
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Lesson Plan
Curated OER

The Minimal Distance Point from the Vertices of a Triangle

For Teachers 9th - 10th
Students calculate the distance from the vertex of a triangle to the center. In this geometry lesson, students find the shortest distance between a point and the vertex of a triangle. They relate this concept of distance to the real world.
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Lesson Plan
Curated OER

Exploring Characteristics Needed to Prove Two Trianlges Congruent

For Teachers 10th
Tenth graders explore congruent triangles.  In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent.  The lesson combines dry erase board activities and the use of technology.
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Activity
101 Questions

Snail's Pace

For Teachers 6th - 8th Standards
Time doesn't fly when you're watching a snail cross a sidewalk. Combining the concepts of the Pythagorean Theorem and the distance, rate, and time formula, learners determine how long it takes a snail to go from one corner of a sidewalk...
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Lesson Plan
Mathalicious

Out of Left Field

For Teachers 9th - 12th Standards
A baseball trajectory and a parabola seem to make the best pair in real-world quadratic applications. Here is a current baseball resource with questions, discussions, and explorations regarding a quadratic function and home run...
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Lesson Plan
Curated OER

Congruence with Robot Gobot

For Teachers 8th - 10th
Students identify the properties of solids and polygons. In this geometry lesson, students identify the different measurements of a triangle. They use congruence parts and theorem to prove their answer.