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...
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...
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...
Curated OER
Arc Length Lesson
Students find the length of the arc of a circle. In this geometry instructional activity, 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...
EngageNY
Unknown Length and Area Problems
What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.
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...
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
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...
Curated OER
Arc Length and Sectors
Find the length of an arc. Students relate central angles to the area and length of a sector and graph circles on the TI to make predictions.
Curated OER
Gateway Arc Length
Learners differentiate and calculate the length of an arc. They define an arc and relate it to the area of a circle and integrate the function to solve the equations. Students use their TI calculators to graph the equation.
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...
Mathematics Assessment Project
Calculating Arcs and Areas of Sectors of Circles
Going around in circles trying to find a resource on sectors of circles? Here is an activity where pupils first complete an assessment task to determine the areas and perimeters of sectors of circles. They then participate in an activity...
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...
Alabama Learning Exchange
Radians: Just Another Way
Serve up angle measurements on paper plates. Pupils use paper plates and paper-folding techniques to create a unit circle with conversions for special angles. Using their plates, learners explore the relationship between angle...
Curated OER
Length of an Arc and Area of a Sector
For 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...
Curated OER
Chords of a Circle
In this geometry worksheet, 10th graders calculate the length of a chord and the distance from the center of a circle or radius. They compare diameter, chords and radius. There are 10 questions with an answer key.
Curated OER
Around the Clock
Middle schoolers discover the relationship between the circumference of a circle and its diameter. They find the length of an arc of a circle.Students use estimation strategies in real-world applications to predict results (i.e.,...
Curated OER
Secants, Tangents and Arcs
Students identify chords and angles. In this geometry lesson, students calculate the length of the chords inside and outside of-the circle. They differentiate between tangent and secant lines.
NASA
Communications and the Lunar Outpost
Can you hear me now? Groups use given information about communication on the moon to determine the maximum distance an astronaut can travel and stay in communication. Using the calculations, they determine what lunar features they can...
Illustrative Mathematics
Designs
A resource that makes for excellent group work as students explore the area and perimeter of different complex designs made up of squares and circles. The commentary gives a clear definition of perimeter, but suggests that group members...
Curated OER
3.14159265
High schoolers discover the value of Pi. In this value of Pi lesson, students measure the circumference and diameter of various circles on their graphing calculator. High schoolers find the ratio of the circumference to the diameter...
Curated OER
Finding Areas of Triangles, Rectangles, and Circles
Students find the areas of geometric shapes. In this geometry lesson plan students find and measure the sides, perimeters, and areas of quadrilaterals, triangles, and circles. Students relate the measures to the others by using formulas.
Curated OER
Length of an Arc
Twelfth graders define an arc and find its length. In this calculus instructional activity, 12th graders roll out a circle and measure its length using the same method of a triangle and its hypotenuse. They apply the Pythagorean Theorem...
Curated OER
Electric Hoist Problem
Students convert angle measures between degrees and radians. They are given a copy of the task sheet with a graphic to help describe the situation. Pupils review the angle and arc relationship in a circle related to length of the...