Lesson Plan
Curated OER

Exploring the Centroid of a Triangle

For Teachers 9th - 12th Standards
Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...
Lesson Plan
Curated OER

Exploring Centers of a Triangle: Part 2

For Teachers 10th - 12th
Learners model and solve a real-world problem by constructing the centroid of a triangle. They explore relationships of the medians of a triangle and investigate how the centroid partitions each of the medians. Students investigate...
Lesson Plan
EngageNY

Special Lines in Triangles (part 2)

For Teachers 9th - 10th Standards
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
Lesson Plan
Curated OER

The Centroid of a Triangle

For Teachers 9th - 10th
Students familiarize themselves with the construct and measure menus. They demonstrate how to use the Sketchpad Calculator. They draw a triangle and construct the centroid. They shade in each of the small triangles and measure the area.
Lesson Plan
Curated OER

Properties of the Centers of a Triangle

For Teachers 9th - 12th Standards
High schoolers investigate properties of the four centers of a triangle and explore a special property of the circumcenter and orthocenter of a triangle. This instructional activity requires the use of Cabri, Jr.
Worksheet
Math eBook

Centroid of Triangles

For Students 9th - 11th
For this centroid of triangles instructional activity, students use given information to determine the centroid of a triangle. They identify the point through which all medians of the triangle pass. This five-page instructional activity...
Lesson Plan
EngageNY

Analytic Proofs of Theorems Previously Proved by Synthetic Means

For Students 9th - 12th Standards
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
Lesson Plan
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Illustrative Mathematics

Placing a Fire Hydrant

For Teachers 9th - 10th Standards
Triangle centers and the segments that create them easily become an exercise in memorization, without the help of engaging applications like this lesson. Here the class investigates the measure of center that is equidistant to the three...
Lesson Plan
Curated OER

Special Segments in a Triangle

For Teachers 10th
In this geometry worksheet, 10th graders review the vocabulary associated with the special segments of a triangle and the associated points of concurrency and solve problems in which they find the indicated missing angle or...
Performance
Radford University

Building a Recreation Center

For Teachers 9th - 12th Standards
It's all about location, location, location. Small groups work to find the best spot for a rec center to serve three different communities. Learners construct the inscribed and circumscribed circles of a triangle to find the best place....
Performance
Radford University

Finding a Location for Your Kitchen Island

For Teachers 9th - 12th Standards
Where is the best place to work? Small groups map out a kitchen on a coordinate plane and find the centers of the work triangle to find the best place to install an island. The teams use algebraic methods to locate the center by finding...
Lesson Plan
Curated OER

Centroid of a Triangle

For Teachers 6th - 9th
Young scholars build on existing knowledge of median and midpoints of triangles. They incorporate their prior knowledge to develop an example of the center of a mass of a triangle. They share their sketches with their classmates.
Unit Plan
Mathematics Vision Project

Geometric Figures

For Teachers 10th - 12th Standards
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
Lesson Plan
Curated OER

Medians and Altitudes of Triangles

For Teachers 10th
In this geometry worksheet, 10th graders determine if a given segment is a median or altitude of a triangle and use then find the indicated missing length or equation of a line.  The two page worksheet contains twenty...
Assessment
Concord Consortium

Always, Sometimes, Never

For Students 9th - 10th Standards
Do your learners always, sometimes, or never remember the properties of the segments in triangles? Get that number closer to always with a creative lesson analyzing all four segments. Scholars consider a statement about one of the...
Worksheet
Curated OER

Triangles

For Students 10th
In this triangles instructional activity, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of...
Lesson Plan
Curated OER

The Centroid : Balancing the History

For Teachers 10th - 12th
Young scholars discover the centroid of a triangle based on Euclid's constructions. They explore locus of points of a median. They understand properties of the segments that form the median and areas of the smaller sections formed by the...
Lesson Plan
Curated OER

Finding The Center Mass of a Triangle

For Teachers 9th - 10th
Students calculate the center mass of a triangle. In this geometry lesson, students use the median to find the center mass. They discuss the different characteristics of triangles and their center of mass.
Worksheet
Curated OER

Regents Exam Questions G.G.21: Centroid, Orthocenter, Incenter, and Circumcenter

For Students 9th - 12th
In this triangles worksheet, learners solve 4 multiple choice problems. Students find the centroid, orthocenter, incenter, and circumcenter or various triangles.
Worksheet
Curated OER

Concurrence

For Students 10th
In this concurrence learning exercise, 10th graders solve 10 different problems related to determining various concurrences. First, they determine which type of triangle has two altitudes outside of it. Then, students determine the...
Lesson Plan
Curated OER

The Search for Pythagoras' Treasure

For Teachers 8th - 10th
Students identify and define properties of triangles. In this geometry lesson, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
Worksheet
Curated OER

Lesson 5.3 Vocabulary Quiz: Concurrent Lines, Medians, & Altitudes

For Students 10th - 12th
In this vocabulary worksheet, students match a given vocabulary word to the correct definition.  Words include such terms as altitude, centroid, circumcenter, circumscribed circle, inscribed circle, median and...
Handout
Math Open Reference

Math Open Reference: Centroid of a Triangle

For Students 9th - 10th
A complete reference guide to the centroid of a triangle. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Activity
Texas Instruments

Texas Instruments: Exploring the Centroid of a Triangle

For Teachers 9th - 10th
In this activity, students investigate what happens when all three medians of a triangle are drawn. They learn how to locate the centroid. [Requires Adobe Reader.]