EngageNY
Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
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...
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...
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.
Curated OER
Measurement of a Central Angle
Students calculate the measurement of a central angle. In this geometry lesson, students identify properties of circles. They use Cabri software to create and analyze graphs.
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...
EngageNY
Unknown Angle Problems with Inscribed Angles in Circles
We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The lesson plan then...
Project Maths
Introduction to Angles
Approach the lesson from the right angle. A discussion-based lesson leads helps learners understand angles in terms of rotation. Individuals use manipulatives to explore the properties of angles and learn how to name them. The lesson is...
Curated OER
Length of an Arc and Area of a Sector
In this length of an arc and area of a sector worksheet, 10th graders solve and complete 12 different types of problems. First, they find the length of an arc in a circle with a given radius and central angle measure. Then, students find...
EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? In this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
Curated OER
Measuring the Earth
High schoolers use principles of geometry to measure the circumference of the Earth. For this applied geometry lesson, students use mathematics to determine scientific information. They make measurements, calculate the central...
Curated OER
Radian Measure
Young mathematicians identify central angles, arcs and radius of circles in this pre-calculus lesson. They identify the proportion of the circle based on its radius while they convert between degrees and radians measurements.
EngageNY
Arc Length and Areas of Sectors
How do you find arc lengths and areas of sectors of circles? Young mathematicians investigate the relationship between the radius, central angle, and length of intercepted arc. They then learn how to determine the area of sectors of...
Curated OER
Arc Measurement Based on The Measurement of a Central Angle
Students define keywords that are important to solve problems. In this geometry lesson, students find the arc length and angle of a circle. They convert between radians and degrees.
Curated OER
Sum of Angles on a Triangle
Use this lesson for a basic review of angles. While the activities discussed are outlined, there are no materials provided to make implementation possible. When using this resource, it is necessary to create worksheets and other...
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
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
Tile Patterns I: Octagons and Squares
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
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.
Alabama Learning Exchange
Cosmic Measurements
Students develop two units of measurement to relate to the astronomical unit and the light year. In this astronomy lesson, students use a Twizzler to develop a measurement unit similar to the astronomical unit. They use a moving object,...
Curated OER
Inscribed Angles
Students calculate the inscribed angle of a triangle. In this geometry instructional activity, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
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
Digger and the Gang
Help online friends Digger and Sprat from the BBC series to solve math problems! In a series of activities, your class will use data sets to calculate measurements, averages, means, and probabilities. The class completes worksheets and...
Curated OER
True North, Magnetic North
Students explain why compass angles need to be corrected for regional magnetic variation. They observe the difference between magnetic and true north. Each student measures the angle of variation for a town in a different state.