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 then...
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
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...
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...
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.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Radford University
Pizza Sector Task
Gobble up a slice of the task. Scholars first consider the area of a whole pizza, half a pizza, and a quarter of a pizza. They then consider other central angles and develop a formula for the area of any sector of a circle.
Mathematics Assessment Project
Inscribing and Circumscribing Right Triangles
High schoolers attempt an assessment task requiring them to find the radii of inscribed and circumscribed circles of a right triangle with given dimensions. They then evaluate provided sample responses to consider how to improve...
Curated OER
Arc Measurement Based on The Measurement of a Central Angle
Young scholars 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
Measuring the Earth
Students use principles of geometry to measure the circumference of the Earth. In this applied geometry lesson, students use mathematics to determine scientific information. They make measurements, calculate the central angle, and...
Curated OER
Angles and Arcs
Students identify the relationship between angles and arcs. In this geometry lesson plan, students rotate and move the circle around to create different arcs on the TI-Navigator. They differentiate between major and minor arcs.
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.
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.
Radford University
Where Should We Sit?
Where's the best seat in the house? Given a diagram of a movie theater, pupils determine the best seats based on the viewing angle. They use inscribed angles to justify their choices.
Curated OER
Arc Length Lesson
Students find the length of the arc of a circle. In this geometry lesson, students calculate the length of an arc and find the measure of the central angle given the length of the arc. They convert between linear and angular speed. They...
Curated OER
The Unit Circle
Students solve problems using the unit circle. In this precalculus lesson, students identify angles using the properties of the unit circle. They observe the trigonometric graphs and sine, cosine and tangent.
Curated OER
Arc Length and Sectors
Find the length of an arc. Learners relate central angles to the area and length of a sector and graph circles on the TI to make predictions.
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.
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
Finding the Area of Regular Polygons
Students analyze relationship between the increase in polygons sides and a circle. In this geometry lesson, students relate the size of the central angle of a polygon, to a circle. They compare the formula for the area of a polygon and a...
Curated OER
Exploring Geometric Figures
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain...
Curated OER
Sectors of Pizza
Young scholars identify the properties of a circle. In this geometry lesson, students relate properties of diameter to sections of a pizza. They calculate the measure of an arc and missing angles.
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
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...