Math Mammoth
Measuring Angles
The first of two pages displays various angles as the measure of degrees of a circular arc. An explanation is written, and learners are asked to model each by holding up two pencils as the rays. The second page provides instruction on...
Teachers' Domain
Introduction to Angle Measure
An all-encompassing package provides video clips that demonstrate real-world activities that have to do with angles. After watching the Cyberchase cartoons, learners discuss why a "v" shape is used to measure a turn. A pair of vital...
Curated OER
Shot Put Arc
Students complete Part A: Dissecting a Circle. They generate their own chords within the circle. Students measure the various parts of the arc in the shot put pit. The first two measurements, the chord and distance from the midpoint of...
MathMovesU
Practice: Measuring Angles and Using a Protractor and More!
Four fabulous worksheets are included in this resource, all having to do with the measurement of angles. On the first, anglers will use a protractor to determine the degrees of 10 different angles. An arc is drawn on each. On the second,...
NASA
It All Comes Full Circle
How long does it take spacecraft go around the earth? Using the circular orbits of the space shuttle and the International Space Station, groups determine the distance traveled in one revolution, then calculate the distance traveled...
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...
CK-12 Foundation
Conversion between Degrees and Radians: Arc and Radians Relationship
How are arc lengths and radians related? An interactive resource demonstrates the relationship as pupils create arc lengths in a unit circle and compare them to the angle measurements. Questions ask individuals to build upon this...
Flipped Math
Circles and Arc Lengths
Discuss all things round and round. Pupils review finding area and the circumference of circles and use them to solve problems. Next, they learn about central angles and their relationships to measures of arcs. Learners then find out how...
Curated OER
Measuring Distance
In this measurement worksheet, students practice drawing 7 specific geometrical lines in a circle. Students problem solve 1 word problem with 3 measurements involving distance.
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...
Virginia Department of Education
Arc Length and Area of a Sector
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
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...
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
Arcs and Central Angles
In this arcs and central angles worksheet, 10th graders solve and complete 25 different types of problems. First, they use the letters shown in the diagram to name each portion. Then, students find the measure of each arc or angle named....
Curated OER
Circles and Cylinders
In this geometry lesson, 10th graders break down a circle and identify the different parts. They discuss chords, diameter, radius, circumference, major and minor segment. There are 42 problems broken down into 5 different sections.
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...
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...
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
EngageNY
Arcs and Chords
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
Curated OER
Circles: Geometry Review Worksheet
Tenth graders solve and complete 14 different geometry problems. First, they find the area and circumference of a circle with a given radius. Then, they find the area between a circle and an inscribed equilateral triangle given the...
Flipped Math
Secants and Tangents
Put the vertex in, put the vertex out. Pupils explore theorems about the relationships of lengths of segments and angles of line segments that intersect inside or outside the circle. Learners use the theorems to solve problems involving...
Radford University
Discover Radians!
No need for radians to be mysterious. Scholars use a cardboard cut-out of a unit circle and measure the radius and circumference using a piece of string. They consider the number of radii needed to cover the entire circumference and use...
Curated OER
Properties of Arcs, Lengths and Chords
Students differentiate between the different properties of arcs, arc lengths, chords, and chord lengths. For this circles lesson, students calculate the arc length of a given circle, and find the measure of the inscribed angles of a...