Lesson Plan
Curated OER

Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Your geometry learners will discover and show the construction of the circumcenter of a triangle. Guided by the steps in the activity, they construct perpendicular bisectors of each side that have a point of concurrency called the...
Lesson Plan
Curated OER

Exploring the Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Students construct the circumcenter of a triangle. In this constructing the circumcenter of a triangle lesson plan, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the triangle....
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.
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...
Lesson Plan
Curated OER

Circumscribing a Circle About a Triangle

For Teachers 9th - 12th Standards
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
Lesson Plan
EngageNY

Points of Concurrencies

For Teachers 9th - 10th Standards
You say that perpendicular bisectors intersect at a point? I concur! Learners investigate points of concurrencies, specifically, circumcenters and incenters, by constructing perpendicular and angle bisectors of various triangles.
Lesson Plan
Curated OER

Bisectors of Triangles

For Teachers 10th
In this geometry worksheet, 10th graders solve problems involving the perpendicular bisectors and angle bisectors of a triangle and their points of concurrency.  The one page worksheet contains sixteen questions.  Answers...
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

Triangles with Collinear Circumcenters

For Teachers 9th - 10th
Learners identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.
Lesson Plan
Curated OER

Exploring Centers of a Triangle: Part 1

For Teachers 9th - 11th
Students use problem solving skills, formal geometry, and The Geometer?s Sketchpad. They model and solve two real-world problems by constructing the in center and circumcenter of triangles.
Lesson Plan
Curated OER

Inscribed Right Triangles

For Teachers 7th - 9th
Learners calculate the measurements of the inscribed angles of a triangle. For this geometry lesson, students relate the hypotenuse of a right triangle and the diameter of a circle to each other. They calculate the diameter of a circle...
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.
Lesson Plan
EngageNY

Construct a Nine-Point Circle

For Students 9th - 10th Standards
There are an infinite number of points on a circle; can you find nine of them? After putting together a nine-point circle, pupils use constructions and their knowledge of triangle segments to determine the center of the circle. Learners...
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...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Circumcenter of a Triangle

For Teachers 9th - 10th Standards
The goal of this task is to construct the circumcenter of a triangle, that is, the point which is the same distance from each of the triangle's three vertices. This task shows that the three perpendicular bisectors of the sides of a...
Activity
Texas Instruments

Texas Instruments: Exploring the Circumcenter of a Triangle

For Teachers 9th - 10th Standards
In this activity, students develop an understanding of the circumcenter of a triangle. Students construct perpendicular bisectors of three sides of a triangle and find the circumcenter.
Handout
Math Open Reference

Math Open Reference: The Circumcenter of a Triangle

For Students 9th - 10th
Learn about the circumcenter of a triangle with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Activity
Texas Instruments

Texas Instruments: Centers of a Triangle

For Teachers 9th - 10th
The centroid, circumcenter, orthocenter, and incenter are the four classic centers of a triangle that are studied in geometry. In this activity, you will construct these center points and discover their properties. [Requires Adobe Reader.]
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Inscribing a Triangle in a Circle

For Teachers 9th - 10th Standards
This problem introduces the circumcenter of a triangle and shows how it can be used to inscribe the triangle in a circle. It also shows that there cannot be more than one circumcenter. Aligns with G-C.A.3.
Activity
Texas Instruments

Texas Instruments: Circumscribing a Circle About a Triangle

For Teachers 9th - 10th Standards
In this activity, students use the distance of the circumcenter of a triangle to each vertex of the triangle as the radius and draw a circle using the circumcenter as the center.
Unit Plan
Cuemath

Cuemath: Point of Concurrency

For Students 9th - 10th
Learn all about the point of concurrency. This lesson targets the point of concurrency of perpendicular bisectors, the point of concurrency of the angle bisectors of a triangle, and has interesting solved examples and practice questions.