EngageNY
Experiments with Inscribed Angles
Right angles, acute angles, obtuse angles, central angles, inscribed angles: how many types of angles are there? Learners first investigate definitions of inscribed angles, central angles, and intercepted arcs. The majority of the lesson...
EngageNY
Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the instructional activity. Young mathematicians build upon concepts learned in the previous instructional activity and formalize the Inscribed Angle Theorem relating inscribed and central angles. The...
EngageNY
The Angle Measure of an Arc
How do you find the measure of an arc? Learners first review relationships between central and inscribed angles. They then investigate the relationship between these angles and their intercepted arcs to extend the Inscribed Angle Theorem...
EngageNY
The Inscribed Angle Alternate – A Tangent Angle
You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their newfound...
West Contra Costa Unified School District
Arcs and Angles
Noah didn't construct this kind of arc. High school scholars first explore how angles can be formed in circles. They then learn relationships between angles and arcs by conducting an exploratory activity where they position and draw arcs...
Curated OER
Cabri Jr. Inscribed Angles
Young scholars construct inscribed angles using Cabri Jr. They draw a circle on their graphing calculator, then construct an inscribed angle and measure its angle measures. Learners drag the inscribed angle around the circle. They make...
Texas Instraments
Angles in Circles
Teach your learners how to investigate the relationship between a central angle and an inscribed angle which subtend the same arc of a circle. The dynamic nature of Cabri Jr. provides opportunity for conjecture and verification.
EngageNY
Secant Angle Theorem, Exterior Case
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous instructional activity to investigate angles created by secant lines that intersect at a point exterior to...
Curated OER
Angles and Arcs
Students identify the relationship between angles and arcs. In this geometry lesson, students rotate and move the circle around to create different arcs on the TI-Navigator. They differentiate between major and minor arcs.
Curated OER
Inscribed Angles
Students calculate the inscribed angle of a triangle. In this geometry lesson, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Curated OER
Inscribed Angles
Students analyze inscribed angles and intercepted arcs and explore the relationships between the two. They investigate the properties of angles, arcs, chords, tangents, and secants to solve problems involving circles.
Curated OER
Properties of Arcs, Lengths and Chords
Students differentiate between the different properties of arcs, arc lengths, chords, and chord lengths. In this circles lesson, students calculate the arc length of a given circle, and find the measure of the inscribed angles of a...
Curated OER
Solving Intercepted Arcs
Students investigate circles and its arcs. In this geometry instructional activity, students identify the relationship between an circle and its intercepted arcs. THey identify the central and inscribed angles.
Curated OER
Circles and Angles
Students identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Texas Instruments
Cabri Jr. Inscribed and Central Angles
Learners will differentiate between inscribed and central angles in this geometry lesson plan. They answer questions dealing with circles as they relate to inscribed triangles and angles. This assignment includes a printable worksheet.
Curated OER
Relationships Among Arc and Angle Measures in Circles
Students follow the directions on the attached worksheet to construct shapes using Geometer's Sketchpad. To start the instructional activity, it is suggested that the teacher guide the students through the initial problem. When...
Curated OER
Inscribed Quadrilaterals and Parallelograms
Learners differentiate between inscribed quadrilaterals and parallelograms. In this geometry lesson, students identify the shaped of the polygons when it is inscribed inside of a circle. They calculate the missing angles of the inscribed...
Curated OER
Solving Problems Involving Chords, Radii, Tangents, Secants and Arcs within the Same Circle
Tenth graders apply their knowledge of angles related to a circle, radii, secants, tangents and chords of a circle. They practice using formulas related to a circle. They also apply what has been practiced to real life situations.
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
Curated OER
Circle Packing
Students identify different parts and properties of circles. In this geometry lesson, students identify the radius, diameter, semicircle and inscribed angle of a circle. They identify the tangent lines to a circle.
EngageNY
Secant Lines; Secant Lines That Meet Inside a Circle
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Curated OER
Plain Figures and Measuring Figures
Students investigate basic geometric concepts. In this geometry lesson, students explore solids through measuring and modeling. This assignment models the importance of understanding concrete objects in geometry.
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...