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 Video
Khan Academy

Khan Academy: Geometry: 2003 Aime Ii Problem 7

9th - 10th
Explanation of 2003 AIME II (American Invitational Mathematics Examination) Problem 7. Finding the area of a rhombus based on the circumradii of triangles. This video also appears in the Geometry: Polygons, quadrilaterals, and...
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: Perpendicular Bisectors: Area Circumradius Formula Proof

9th - 10th Standards
Proof of the formula relating the area of a triangle to its circumradius.