Instructional Video4:16
Curated Video

Finding Circumcenters and Incenters of a Triangle Using Angle Bisectors, Perpendicular Bisectors, and Circles

K - 5th
In this lesson, students will learn how to find the circumcenter and incenter of a triangle using angle bisectors, perpendicular bisectors, and circles. They will understand the concept of different centers in a triangle and how they...
Instructional Video2:54
Curated Video

Constructing a Circumscribed Circle on a Triangle Using Perpendicular Bisectors

K - 5th
In this lesson, students will understand that a circumscribed circle is a circle that passes through all the vertices of a polygon, and that its center is where the perpendicular bisectors of the polygon intersect. By following...
Instructional Video5:47
Professor Dave Explains

Special Lines in Triangles: Bisectors, Medians, and Altitudes

12th - Higher Ed
Working with triangles.
Instructional Video
Khan Academy

Khan Academy: Geometry: Euler Line

9th - 10th Standards
Demonstrates that the circumcenter, orthocenter, and centroid of a triangle all lie on a line called an Euler line. [6:12]
Instructional Video
Khan Academy

Khan Academy: Geometry: Three Points Defining a Circle

9th - 10th Standards
Demonstates that any three non-collinear points can be used to define a unique triangle with a unique circumcenter and circumradius. These, in turn, define a unique circle. The center of the circle is the circumcenter of the triangle....
Instructional Video
Khan Academy

Khan Academy: Algebra: Conic Sections: Three Points Defining a Circle

9th - 10th Standards
A video lesson that describes how any three non-collinear points actually define a circle. First it is shown that three points define a triangle. Then it is shown that the circumcenter of that triangle is actually the center of the...
Instructional Video
Khan Academy

Khan Academy: Geometry: Circumcenter of a Right Triangle

9th - 10th Standards
Proves that the circumcenter of a right triangle is the midpoint of the hypotenuse. [5:42]
Instructional Video
Khan Academy

Khan Academy: Geometry: Circumcenter of a Triangle

9th - 10th Standards
Explains using multiple proofs that a point on a perpendicular bisector is equidistant from the endpoints of the segment it bisects. Proofs use triangle congruency postulates. Lays the foundation for understanding the circumcenter of a...
Instructional Video
Khan Academy

Khan Academy: Triangles: Euler Line

9th - 10th
A video demonstration of the magic and mystery of the Euler Line.
Instructional Video
Khan Academy

Khan Academy: Triangles: Review of Triangle Properties

9th - 10th Standards
Provides a review of perpendicular bisectors, angle bisectors, medians, and altitudes and the special points of concurrency formed by these parts of a triangle.
Instructional Video
Khan Academy

Khan Academy: Triangles: Circumcenter of a Triangle

9th - 10th Standards
Multiple proofs showing that a point is on a perpendicular bisector of a segment if and only if it is equidistant from the endpoints. Using this to establish the circumcenter, circumradius, and circumcircle for a triangle.
Instructional Video
Khan Academy

Khan Academy: Triangles: Circumcenter of a Right Triangle

9th - 10th Standards
The video tutorial shows that the midpoint of the hypotenuse is the circumcenter.
Instructional Video
Khan Academy

Khan Academy: Geometry: Euler's Line Proof

9th - 10th Standards
Proves that the circumcenter, orthocenter, and centroid all lie on the same line, the Euler line. Proof relies on understanding of properties of similar triangles and properties of special parts of a triangle. [9:50]