Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Right Triangles Inscribed in Circles Ii

For Teachers 9th - 10th Standards
For this task, students analyze the characteristics of a right triangle that has two sides labeled with midpoints and show that the triangle is inscribed in a circle with a diameter the length of its hypotenuse. Aligns with G-C.A.2.
Handout
Geometry Help

Geometry Help: Arcs, Angles, and Sectors

For Students 9th - 10th Standards
Explains the basic concept of arcs, angles, and sectors with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Activity
Texas Instruments

Texas Instruments: Inscribing a Circle in a Triangle

For Teachers 9th - 10th
In this activity, students bisect the angles of a triangle and find the incenter of the triangle. They find the distance from the incenter to the side of the triangle and use it as radius. With the incenter as the center, they inscribe a...
Activity
Texas Instruments

Texas Instruments: Cabri Jr. Inscribed and Central Angles

For Teachers 9th - 10th Standards
This activity uses Cabri Jr. to explore the relationship between inscribed and central angles subtended from the same arc of a circle.
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Circles

For Students 9th - 10th
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...
Handout
Wolfram Research

Wolfram Math World: Inscribed Angle

For Students 9th - 10th Standards
This site provides not only a definition of inscribed angle but also links to related terms.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: g.c Inscribing a Circle in a Triangle Ii

For Teachers 9th - 10th Standards
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.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C, G Co Tangent Lines and the Radius of a Circle

For Teachers 9th - 10th Standards
In this task, students are shown a circle with center O and point P on the circle. L is a line that is a tangent to the circle at P. They must show that line OP is perpendicular to line L. Aligns with G-C.A.2, G-CO.A, and G-CO.C.9.
Unknown Type
Khan Academy

Khan Academy: Quiz: Inscribed Quadrilaterals

For Students 9th - 10th Standards
Use the fact that opposite angles in an inscribed quadrilateral are supplementary to solve a few problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unit Plan
Khan Academy

Khan Academy: Challenge Problems: Inscribed Shapes

For Students 9th - 10th Standards
Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.
Activity
Ministry of Education and Universities of the Region of Murcia (Spain)

Ministerio De Educacion Y Ciencia: Ingulos en Una Circumferencia

For Students 9th - 10th Standards
In Spanish. This site discusses the angles relative to the circles. It defines the concept of central angle, inscribed, interior, exterior and some important geometric outcomes and applications which uses these concepts.
Lesson Plan
Texas Instruments

Texas Instruments: Segments Formed by Intersecting Chords, Secants, and Tangents

For Teachers 9th - 10th Standards
This activity is designed to help students discover several important theorems concerning lengths of segments formed by intersecting chords, secants, and tangents.
Lesson Plan
Texas Instruments

Texas Instruments: Chords, Secants, and Tangents

For Teachers 9th - 10th Standards
Students construct chords, secants, and tangents. From those constructions, they develop a deeper understanding of the terms, as well as explore certain properties of the constructions.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Gpe.5 Triangles Inscribed in Circle

For Teachers 9th - 10th Standards
For this task, students use ideas about linear functions to determine when certain angles are right angles. They use the fact that two lines (if not vertical or horizontal) are perpendicular when their slopes are inverse reciprocals, as...
Unit Plan
Mangahigh

Mangahigh: Shape: Quadrilaterals Inscribed in Circles

For Students 9th - 10th Standards
Determine the missing angle measures of quadrilaterals inscribed in circles.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Classifying Triangles

For Teachers 9th - 10th Standards
The goal of this task is to help students synthesize their knowledge of triangles where only two of the vertices have been given. They will need to know that a triangle inscribed in a circle, with a diameter of the circle as one side, is...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Origami Equilateral Triangle

For Teachers 9th - 10th Standards
The purpose of this task is to explore reflections in the context of paper folding. Each fold is associated with a line of reflection and understanding each step in the construction requires careful analysis of angles and of the...
Handout
Math Words

Mathwords: Inscribed Circles

For Students 9th - 10th Standards
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.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Locating Warehouse

For Teachers 9th - 10th Standards
You have been asked to place a warehouse so that it is an equal distance from three roads on a map. Learners must fold a paper so that this point is where two folds intersect, and they must explain why their construction works and why...