Lesson Plan
EngageNY

The Inscribed Angle Alternate – A Tangent Angle

For Teachers 9th - 12th Standards
You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their...
Lesson Plan
EngageNY

Tangent Lines and the Tangent Function

For Teachers 11th - 12th Standards
Construct tangent lines and make the connection to tangent functions. An informative lesson reviews the geometry origins of the tangent function. Pupils use that information to determine how to construct a tangent to a circle from a...
Lesson Plan
EngageNY

Why Call It Tangent?

For Students 10th - 12th Standards
Discover the relationship between tangent lines and the tangent function. Class members develop the idea of the tangent function using the unit circle. They create tables of values and explore the domain, range, and end behavior of...
Lesson Plan
EngageNY

Tangent Segments

For Teachers 9th - 12th Standards
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
Activity
Illustrative Mathematics

Tangent to a Circle From a Point

For Teachers 9th - 10th Standards
Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using...
Lesson Plan
EngageNY

Properties of Tangents

For Teachers 9th - 12th Standards
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...
Lesson Plan
EngageNY

Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams

For Teachers 9th - 12th Standards
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...
Lesson Plan
EngageNY

Secant Lines; Secant Lines That Meet Inside a Circle

For Teachers 9th - 12th Standards
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
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...
Lesson Plan
Virginia Department of Education

Circles in the Coordinate Plane

For Teachers 9th - 11th Standards
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...
Worksheet
Mt. San Antonio Collage

Circles

For Students 9th - 12th Standards
Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated learning exercise provides guided practice through many topics such as central angles, inscribed...
Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Interactive
CK-12 Foundation

Trigonometric Functions and Angles of Rotation: The Triangle in the Circle

For Students 10th - 12th Standards
Go around the unit circle and create triangles. Pupils move a point around the unit circles to visualize the triangle associated with the angle in standard position. The three main trigonometric functions are defined in terms of the legs...
Assessment
Concord Consortium

Orthogonal Circles

For Students 7th - 12th Standards
Here's some very interesting circles for your very interested pupils. A performance task requires scholars to sketch a pair of orthogonal circles so the centers are the endpoints of one side of a triangle. They draw an additional circle...
Interactive
CK-12 Foundation

Unit Circle: Medieval Castle Defense

For Students 10th - 12th Standards
Who needs a plan — let trigonometry protect you! Pupils determine the angle of an approaching enemy to a village wall. The scholars determine the exact value of trigonometric functions for the angle. Class members use trigonometry to...
Interactive
CK-12 Foundation

Tangent Graphs: Slope and Angle

For Students 10th - 12th Standards
Learning about tangents doesn't have to be a slippery slope. Pupils drag a point around a unit circle to see how angle affects the slope of a line. They individually answer a set of challenge questions to come to the conclusion that...
Lesson Plan
EngageNY

Secant Angle Theorem, Exterior Case

For Teachers 9th - 12th Standards
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous lesson to investigate angles created by secant lines that intersect at a point exterior to the circle....
Interactive
CK-12 Foundation

Reference Angles and Angles in the Unit Circle: Exploring Reference Angles

For Students 10th - 12th Standards
A steal of a deal — get four angles for the value of one. An interactive resource allows individuals to visualize all four angles that have the same reference angle. Pupils answer questions by using the interactive to create the...
Assessment
Concord Consortium

Shooting Arrows through a Hoop

For Students 9th - 12th Standards
The slope makes a difference. Given an equation of a circle and point, scholars determine the relationship of the slope of a line through the point and the number of intersections with the circle. After graphing the relationship, pupils...
Activity
Illustrative Mathematics

Satellite

For Teachers 9th - 11th Standards
Learners practice relating rules of trigonometry and properties of circles. With a few simplifying assumptions such as a perfectly round earth, young mathematicians calculate the lengths of various paths between satellite and...
Lesson Plan
West Contra Costa Unified School District

Arcs and Angles

For Teachers 9th - 12th
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...
Unit Plan
EngageNY

Complex Numbers and Transformations

For Teachers 11th - 12th Standards
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
Lesson Plan
EngageNY

Secant and the Co-Functions

For Students 10th - 12th Standards
Turn your class upside down as they explore the reciprocal functions. Scholars use the unit circle to develop the definition of the secant and cosecant functions. They analyze the domain, range, and end behavior of each function.
Interactive
CK-12 Foundation

Trigonometric Functions of Angles Greater than 360 Degrees: Snowboarding

For Students 10th - 12th Standards
Spin through the trigonometric functions. Scholars determine the angle of rotation a snowboarding snowman makes at various distances in his jump. The class members then calculate the values of trigonometric functions for those angles.