Curated OER
Pi Day
Ninth graders explore the concept of pi in preparation for developing a project for pi day. They examine direct variation, the history of pi, circle circumference and arc length, area and sector area and then consider how these concepts...
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
Angles and Arcs
Students discuss the sum of central angles and use string to create them on circles. They find the measure and length of both minor and major arcs.
Students give examples of concentric, similar, and congruent circles and congruent arcs.
Oswego City School District
Regents Exam Prep Center: Circles: Area of Sectors and Segments
Material to supplement classroom instruction on sectors and segments of circles. Find guidelines on how to find the area of sectors and segments, as well as a multiple-choice quiz, and an activity idea called "Sectors and Pizza."
CK-12 Foundation
Ck 12: Trigonometry: Area of a Sector
[Free Registration/Login may be required to access all resource tools.] Find the area of a sector of a circle.
Khan Academy
Khan Academy: Area of a Sector
Relate the area of a sector to the area of a whole circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Texas Instruments
Texas Instruments: Arc Length and Area of Sectors
This is an introduction to finding the arc length and area of sectors of circles. Students should have the formulas for Circumference and Area of circles.
Texas Education Agency
Texas Gateway: Determining Area: Sectors of Circles
Students will use proportional reasoning to develop formulas to determine the area of sectors of circles. Students will then solve problems involving the area of sectors of circles.
CK-12 Foundation
Ck 12: Geometry: Area of Sectors and Segments
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a sector or segment. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
CK-12 Foundation
Ck 12: Geometry: Area of a Circle
[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate the area of circles and the area of sectors of circles by using given information and formulas. Students examine guided notes,...
Math Is Fun
Math Is Fun: Circle Sector and Segment
Learn about the "two main 'slices' of a circle" called a sector and a segment, and see how you can calculate the area of a sector or segment using trigonometry.
CK-12 Foundation
Ck 12: Geometry: Area of Sectors and Segments
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to find the area of sectors and segments of circles. Students examine guided notes, review guided practice, watch instructional...
Sophia Learning
Sophia: Finding a Formula for the Surface Area of a Cone
This video tutorial demonstrates how to find the formula for the surface area of a cone.
Johan Claeys
Math Abundance: The Circle: Basic Concepts
Goes over the equation of a circle, parametric equations of a circle, intersection of circle and line, tangent line in a point of a circle, etc.
Cuemath
Cuemath: Circles
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
Math2
Math2: Circles
This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...
Sophia Learning
Sophia: Sector Area of a Circle: Lesson 2
This lesson will demonstrate how to find the area and radius of a circle when given the sector area and central angle measure. It is 2 of 8 in the series titled "Sector Area of a Circle."
Sophia Learning
Sophia: Sector Area of a Circle: Lesson 4
This lesson will demonstrate how to find the area and radius of a circle when given the sector area and central angle measure. It is 4 of 8 in the series titled "Sector Area of a Circle."
Illustrative Mathematics
Illustrative Mathematics: G C Mutually Tangent Circles
Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...
Math Words
Math Words: Sector of a Circle
This site offers a picture and short discussion of a sector of a circle. The site contains a link to the area of a sector of a circle in both degrees and radians. There are links to related words.
CK-12 Foundation
Ck 12: Area of Sectors and Segments: Pacman Area
[Free Registration/Login Required] Students are to determine the area of the shaded region between two radii. Click challenge me to answer practice questions and click learn more to watch a video.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Analyze Math
Analyze Math: Sectors and Circles Problems
Try these three problems regarding area of sectors, length of arcs, and central angles. The problems will challenge and intrigue sharp geometry students. Detailed written solutions are included.
Mr. Martini's Classroom
Mr. Martini's Classroom: Circles Geometry Review
This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.