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...
Mathematics Assessment Project
Circles in Triangles
Circles, and triangles, and tangents, oh my! In the assessment task, learners first answer questions leading to the radius of an inscribed circle for a given right triangle. They then use the result to independently determine the radius...
EngageNY
Recognizing Equations of Circles
What does completing the square have to do with circles? Math pupils use completing the square and other algebraic techniques to rewrite equations of circles in center-radius form. They then analyze equations of the form x^2 + y^2 + Ax +...
CK-12 Foundation
Trigonometric Functions and Angles of Rotation: The Triangle in the Circle
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...
CK-12 Foundation
Unit Circle: Medieval Castle Defense
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...
Curated OER
Circles
In this circles activity, 10th graders solve 10 different problems that include determining the chords, secants, and tangents of circles shown. First, they determine 4 different line segments given a circle with secants and chords with...
Curated OER
Finding the Sum of the Perimeters of 3 Small Circles
For this geometry worksheet, students find the sum of the perimeters of three small circles. These small circles are tangent to each other and to a larger circle. The centers of the small circles have their centers on the diameter of...
Curated OER
Tangents and Circles
In this tangents and circles worksheet, 10th graders solve 10 different problems that include various tangents and circles. First, they determine in each diagram whether the segments shown are tangents or not. Then, students determine...
Flipped Math
Unit Circle and Radians
Measure angles is easy as pi. Pupils review special right triangles to find exact values for trigonometric functions. Scholars learn about radians and how they connect to measurements in degrees. They find exact and approximate values of...
Texas Instruments
Exploring Tangents
Explore the concept of tangent lines. In this tangent line lesson, learners graph a circle and two lines on their graphing calculator using Cabri Jr. Students construct the lines so that they both intersect at a given point and are both...
Curated OER
Tangent Lines and the Radius of a Circle
Your Geometry learners will collaboratively prove that the tangent line of a circle is perpendicular to the radius of the circle. A deliberately sparse introduction allows for a variety of approaches to find a solution.
Concord Consortium
Circumscribed Polygon
Trigonometry teachers often go off on a tangent, and here's a activity that proves it! First, young mathematicians use a formula with tangent to prove a formula correct for area. Then, they draw conclusions about the area of a circle...
CK-12 Foundation
Tangent Graphs: Slope and Angle
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...
Alabama Learning Exchange
Unit Circle: Special Angles—Just Know One
It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.
Concord Consortium
Orthogonal Circles
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...
CK-12 Foundation
Reference Angles and Angles in the Unit Circle: Exploring Reference Angles
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...
Curated OER
Tangent Properties
For this geometry worksheet, 10th graders solve problems based on the properties of lines tangent to one or more circles. Constructions are included. The one page worksheet contains eight questions. Answers are not included.
Curated OER
Tangents
In this tangents activity, students determine the length of a missing side of a right triangles. They use tangent lines to solve problems. This two-page activity contains 11 multi-step problems.
Curated OER
Tangents Multiple Choice
In this circles worksheet, students solve 10 multiple choice problems. Students use a diagram of a circle with tangent lines and segment bisectors to answer each question. Students find unknown segment lengths using the given information.
Curated OER
Arcs and Angles Formed by a Tangent and a Chord
In this math worksheet, 10th graders solve problems involving a tangent line intersection the arc and forming various angles. There are 6 problems to be solved.
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
Tangents, Secants, and Chords
For this tangents, secants and chords worksheet, 10th graders identify and solve 48 different problems that include using 3 different theorems for defining circles. First, they determine the area of each circle with C as the center and a...
Curated OER
Circles
In this circles learning exercise, 10th graders solve and complete 13 various types of problems. First, they solve each set of triangles for the given variable. Then, students name a radius, a diameter, a tangent, a secant, a point of...
Curated OER
Angles in Circles
In this angles in circles worksheet, 10th graders solve 10 different problems that include tangents and chords and intersecting chords. First, they find x when given 2 intersecting chords. Then, students determine x given the diameter...