EngageNY
Secant Lines; Secant Lines That Meet Inside a Circle
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
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...
Illustrative Mathematics
The Circle and The Line
Here is a resource where algebra learners show their understanding of a system of equations involving a circle and a line. Once graphed, learners see two points of intersection, one where the ordered pair is read, and a second where...
Illustrative Mathematics
Tangent to a Circle From a Point
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 information about...
Mathematics Vision Project
Circles: A Geometric Perspective
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...
EngageNY
Secant Angle Theorem, Exterior Case
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous instructional activity to investigate angles created by secant lines that intersect at a point exterior to...
Texas Instruments
Drawing a Line Tangent to a Circle
Explore lines tangent to a circle. In this math lesson, students manipulate circles and lines on a TI calculator. They draw a circle and analyze perpendicular lines intersecting the circle in only one place. This activity works best if...
Curated OER
Conjectures of Intersecting Circles
Young scholars make conjectures of intersecting circles. In this geometry activity, students observe circles and their position in space. They investigate and observe two and three dimensional objects.
CK-12 Foundation
Vertical Line Test: Exploration
What do vertical lines have to do with functions? Individuals slide a vertical line through four different graphs. They use that vertical line test to determine if the graphs represent functions.
Curated OER
Circles Terminology Multiple Choice
In this circles worksheet, students solve 10 multiple choice problems. Students answer questions about diameter and chord relationships, tangent lines to a circle, circumference, the Pi relationship, etc.
Inside Mathematics
Circles in Triangles
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...
Curated OER
Conjectures For Intersecting Circles
Students identify properties of circles. In this geometry lesson, students identify the center of two intersecting circles.They use Cabri software to create circles and move it around to make observation.
Flipped Math
Secants and Tangents
Put the vertex in, put the vertex out. Pupils explore theorems about the relationships of lengths of segments and angles of line segments that intersect inside or outside the circle. Learners use the theorems to solve problems involving...
Dick Blick Art Materials
Start with a Circle...
The Golden Ratio. The Divine Proportion. Yup. It's math and art blended into one colorful activity. Young artists combine colored tissue paper circles and parts of circles to create geometric patterns. As a bonus, kids get to figure out...
Curated OER
Concurent Circles I
In this concurrent circles using GeoGebra worksheet, students solve 2 short answer problems. Students construct concurrent circles using the GeoGebra software and determine why their construction of circles are concurrent. Students...
Utah Education Network (UEN)
The Angle Tangle
Fourth and fifth graders identify three types of angles, recognize that angles are measured in degrees, measure angles using protractors or angle rulers. They classify angles as a class, classify angles on pattern blocks, and complete a...
Curated OER
Concurent Circles II
For this geometry worksheet, students draw a shape based on the directions. They tell the reasons the four resulting circles are concurrent. A sample drawing is included.
Curated OER
Angles in Circles
For 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...
Curated OER
Altitudes and Orthocenters: Making Connections to the Nine-Point Circle
Students practice various equations for constructing nine-point circles for triangles.
Curated OER
Intersecting Lines and Segments of Measures
Mathematicians measure intersecting lines-and circles, and create chords. For this geometry lesson, students explore interrior and exterior chords created by tangent and secant lines. These segments can be inside the circleor outside the...
Curated OER
Circles and Angles
Students identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Concord Consortium
Shooting Arrows through a Hoop
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...
EngageNY
The Inscribed Angle Alternate – A Tangent Angle
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 newfound...
EngageNY
Tangent Segments
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...