Curated OER
Circles and Squares
In this area worksheet, students find the ratio of 1 area problem. Students find the ratio of areas of inscribed circles to circumscribed squares.
Science Buddies
Science Buddies: Inscribing a Circle in a Triangle Using the Geometry Applet
Here is a project that combines Computer Science and Mathematics. Prove a method for inscribing a circle within a triangle (as shown). You'll also learn how to create an interactive diagram to illustrate your proof, using an applet that...
Math Planet
Math Planet: Geometry: Inscribed Angles and Polygons
Inscribed angles and polygons are investigated through examples and a video lesson. [0:42]
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Circles
Practice using your graphing calculator for drawing circles and for finding measurements for circles and parts of the circle. If you get stumped or if you would like to check your work, then select the View Solution button, which is...
Analyze Math
Analyze Math: Regular Polygons
The interactive tutorial examines the properties and formulas of regular polygons, inscribed circles, and circumscribed circles.
Illustrative Mathematics
Illustrative Mathematics: g.c Inscribing a Circle in a Triangle Ii
This task focuses on a fact which comes out of the construction of the inscribed circle in a triangle: the angle bisectors of the three angles of triangle ABC all meet in a point. Aligns with G-C.A.3.
Illustrative Mathematics
Illustrative Mathematics: g.c Inscribing a Circle in a Triangle I
The goal of this task is to show how to draw a circle which is tangent to all three sides of a given triangle: that is, the circle touches each side of the triangle in a single point. Aligns with G-C.A.3.
CK-12 Foundation
Ck 12: Inscribed and Circumscribed Circles of Triangles
[Free Registration/Login Required] Students will move points on a circle to determine the relationships between the inscribed and circumscribed circles of triangles. Click 'Challenge Me' to answer practice questions.
Math Open Reference
Math Open Reference: Incircle
A complete reference guide to incircles. It provides definitions and examples that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: The Incircle of a Triangle
Learn about the incircle 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.
Khan Academy
Khan Academy: Inscribed Quadrilaterals
Use the fact that opposite angles in an inscribed quadrilateral are supplementary to solve a few problems.
CK-12 Foundation
Ck 12: Interactive Geometry: 8.5 Inscribed and Circumscribed Circles of Triangle
Learn how an inscribed circle is the largest circle contained within the triangle.
Khan Academy
Khan Academy: Challenge Problems: Inscribed Shapes
Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.
Math Words
Mathwords: Inscribed Circles
Mathwords provides an explanation and a diagram of an inscribed circle. By clicking on any of the highlighted words, you will learn about related terms.