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Lesson Plan
Curated OER

Indirect Measurement with Similar Triangles

For Teachers 9th - 12th
Students use similar triangles to find missing heights.  In this using similar triangles to find missing heights instructional activity, students use proportions to find the heights of missing side lengths.  Students find the height of...
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Lesson Plan
Curated OER

Measurement of Objects Using Similar Triangles in The Plane

For Teachers 9th - 11th
Students use similar triangles and a sight tool to find the height and distance between large objects. In this similar triangles lesson plan, students use a constructed sight tool to measure the distance and height of an object using an...
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Unit Plan
1
1
Mathematics Vision Project

Similarity and Right Triangle Trigonometry

For Teachers 10th - 12th Standards
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
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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
Curated OER

Similar Triangles

For Teachers 9th
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.
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Lesson Plan
Curated OER

Similar Triangles - Applied Problems

For Teachers 9th - 12th
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.
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Lesson Plan
EngageNY

Between-Figure and Within-Figure Ratios

For Teachers 9th - 10th Standards
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...
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Lesson Plan
Curated OER

Tennis Triangle

For Teachers 9th - 12th
Learners calculate the height of a tree or flagpole. They measure the shadow of the tree or flagpole and the length of a shadow of a meterstick. Using similar triangles, calculate the heigh. Devise two additional ways in which to measure...
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Lesson Plan
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Illustrative Mathematics

Equal Area Triangles on the Same Base II

For Teachers 9th - 12th Standards
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
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Performance
Radford University

How Tall is the Tree?

For Teachers 9th - 12th Standards
Pairs or small groups work together to determine the height of a tree using similar triangles. Learners make a judgement which direction to let a tree fall to avoid hitting any structures. They then write letters to the principal...
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Worksheet
Curated OER

Parts of Similar Triangles

For Students 10th
In this parts of similar triangles worksheet, 10th graders solve and complete 15 different statements related to naming the parts found in similar triangles. First, they identify each definition stated that describes an everyday usage of...
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Performance
Radford University

REALLY Tall!

For Teachers 9th - 12th Standards
Conduct indirect measurements three ways. Working in groups, pupils come up with different ways to measure three tall objects indirectly. The teacher provides measurement information requested by the teams, and learners then calculate...
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Lesson Plan
Curated OER

II Similar

For Teachers 8th - 10th
Pupils, through lecture and guided practice, discover the properties of similar triangles. They use given measurements of one triangle to find a missing measurement of a similar triangle. They apply this knowledge in real-life...
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Lesson Plan
Project Maths

Introduction to Trigonometry

For Teachers 9th - 12th Standards
The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...
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Lesson Plan
Curated OER

Measuring Heights With Triangles

For Teachers 8th - 10th
Students identify the different properties of triangles. In this geometry lesson, students differentiate between congruent and similar triangles. They use mathematical reasoning to solve word problems.
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Interactive
CK-12 Foundation

Angles of Elevation and Depression: Fly-By Calibration

For Students 9th - 12th Standards
Determine the distance between two trees from afar. Pupils use an interactive resource to create two right triangles using trees and a plane. They determine the horizontal legs of each triangle to find the distance between the two trees.
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Lesson Plan
Willow Tree

Area of Common Geometric Figures

For Students 8th - 11th Standards
Scholars can use area formulas, but can they apply what they know about area? The lesson plan challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and...
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Activity
Big Kid Science

Measuring Shadows Using an Ancient Method

For Teachers 8th - 12th Standards
How did ancient peoples determine the height of really tall objects? Young scientists and mathematicians explore the concept of using shadows to measure height in a hands-on experiment. Paired pupils measure shadows, then calculate the...
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Lesson Plan
Curated OER

Altitude Locator

For Teachers 9th - 12th
High schoolers use protractors, strings, and straws to construct a device used to determine the height of tall objects. In this applied geometry lesson, students use common objects to construct a tangent height guide. They use principles...
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Lesson Plan
EngageNY

General Pyramids and Cones and Their Cross-Sections

For Teachers 9th - 10th Standards
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...
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Worksheet
Curated OER

Area and Periemeter

For Students 10th
In this geometry worksheet, 10th graders determine the area and perimeters of various quadrilaterals and triangles.  The one page worksheet contains ten problems.  Answers are not provided. 
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Lesson Plan
Curated OER

How to weigh a tree

For Teachers 6th - 12th
Students pick a tree they see everyday. They measure the tree's circumference and estimate its height using similar triangles. Students are introduced to Computational Science. They use computers and calculators to compute values...
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Lesson Plan
Curated OER

CORNER CABINET

For Teachers 9th - 10th
Ninth and tenth graders calculate the length, width, height, perimeter, area, volume, surface area, angle measures or sums of angle measures of common geometric figures. They solve problems involving scale drawings, models, maps or...
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Lesson Plan
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EngageNY

Definition and Properties of Volume

For Teachers 9th - 10th Standards
Lead a discussion on the similarities between the properties of area and the properties of volume. Using upper and lower approximations, pupils arrive at the formula for the volume of a general cylinder.