Illustrative Mathematics
Lines of Symmetry for Circles
Further your instruction on geometrical symmetry with an investigation of circles. Fourth graders come to realize that the lines of symmetry of a circle are infinite.
CK-12 Foundation
Length of a Chord: Distance Across a Ferris Wheel
An interactive presents two friends on a ferris wheel with the task of finding the distance between the them. Pupils create the chord between the two friends and calculate its lengths using trigonometric ratios.
Virginia Department of Education
Going the Distance
Estimate the value of one of the most famous irrational numbers. The hands-on lesson instructs classmates to measure the circumference and diameters of circles using yarn. The ratio of these quantities defines pi.
CK-12 Foundation
Angles of Rotation in Standards Positions: Clock Angles
Use a clock face to develop angles representing standard position angles. The interactive allows pupils to create angles using the hands of a clock. Scholars discover that there is a difference in the angle formed using a clock face and...
Teach Engineering
Discovering Relationships Between Side Length and Area
Consider the relationship between side length and area as an input-output function. Scholars create input-output tables for the area of squares to determine an equation in the first installment of a three-part unit. Ditto for the area of...
Noyce Foundation
What's Your Angle?
Math can be a work of art! Reach your artistic pupils as they explore angle measures. A creative set of five problems of varying levels has young learners study interior and exterior angle measures of polygons. The introductory levels...
Virginia Department of Education
Circles in the Coordinate Plane
Make the connection between the distance formula and the equation of a circle. The teacher presents a lesson on how to use the distance formula to derive the equation of the circle. Pupils transform circles on the coordinate plane and...
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...
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
Quadratic Curve of Best Fit
Class members create a table of the number of chords that can be drawn given the number of points on a circle. Pupils analyze the data created, find a function to fit to it, and use the function to make further predictions.
Mathed Up!
Area and Circumference of Circles
Don't go around and around, help your class determine amounts around and in a circle with a video that connects circumference to the perimeter or the distance around an object. The resource includes 14 questions dealing with circles and...
Mathed Up!
Area of Sector and Length of Arcs
Viewers learn how to apply proportional reasoning to find area of sectors and arc lengths with a video that starts off explaining how to find the areas of circle sectors and the lengths of arcs. Scholars then practice solving problems...
Mathed Up!
Circle Theorems
Explore theorems involving circles. Individuals watch a video that reviews the basic parts of a circle. They learn about circle theorems and compete a worksheet of problems that use these theorems — putting their skills to work right away!
Mathematics Assessment Project
Modeling Motion: Rolling Cups
Connect the size of a rolling cup to the size of circle it makes. Pupils view videos of cups of different sizes rolling in a circle. Using the videos and additional data, they attempt to determine a relationship between cup measurements...
Curated OER
Worksheet for Pi
Who needs a pie-eating contest when you have a pi-ology game! Celebrate March 14th with a fun board game about pi and other geometric concepts. As learners answer questions about geometry, they move around the board to collect tokens.
Balanced Assessment
Oops! Glass Top
A short assessment asks participants to find the original radius required to replace a table top. The problem provides a hypothetical situation of having a segment of a broken glass table top. Pupils find the radius of the circular top...
Balanced Assessment
Bicycle Chain II
Apply geometric concepts to a design problem. Individuals examine the structural setup of the chain on a bicycle and use the measurements of the circles to determine the length of the chain.
EngageNY
Examples of Dilations
Does it matter how many points to dilate? The resource presents problems of dilating curved figures. Class members find out that not only do they need to dilate several points but the points need to be distributed about the entire curve...
Balanced Assessment
Square and Circle
To determine the dimensional change to quadruple the area, class members determine how to increase the dimensions of a square and a circle to increase the perimeter by a given factor. they then calculate the necessary factor to create...
EngageNY
Tangent Lines and the Tangent Function
Construct tangent lines and make the connection to tangent functions. An informative instructional activity reviews the geometry origins of the tangent function. Pupils use that information to determine how to construct a tangent to a...
Balanced Assessment
School Zone
Find the right house within walking distance from school. The short assessment has pupils determine the houses that are a given maximum distance from a school. Individuals then determine the shortest and longest walks from the homes that...
EngageNY
Mid-Module Assessment Task: Pre-Calculus Module 4
Challenge scholars to show what they know about properties and addition and subtraction formulas for trigonometric functions. The resource provides a mid-unit check on the progress toward mastery of trigonometric concepts. The areas...
Balanced Assessment
Fit-Ness
Serve four towns with one bus route. Pupils develop a bus route that meets certain criteria to serve four towns. They determine which of the routes would best serve all of them. Individuals then hypothesize where a fifth town should be...
Balanced Assessment
Curvy-Ness
Curves ahead! Develop a numerical measurement of curvy-ness. The class is challenged to come up with a definition of curvy that can be applied to curves. The class members use their defined measurement to describe a curve.