Activity
Curated OER

Inscribing a Square in a Circle

For Teachers 9th - 11th Standards
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
Lesson Plan
EngageNY

Construct a Square and a Nine-Point Circle

For Students 9th - 10th Standards
Anyone can draw a square, but can you CONSTRUCT a square? Here is a resource that challenges math scholars to create steps to finish their own construction. They test their ability to read and follow directions to complete a construction...
Lesson Plan
Willow Tree

Line Graphs

For Students 9th - 12th Standards
Some data just doesn't follow a straight path. Learners use line graphs to represent data that changes over time. They use the graphs to analyze the data and make conclusions.
Worksheet
Curated OER

Tangents and Circles

For Students 10th
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...
Lesson Plan
Virginia Department of Education

Angles, Arcs, and Segments in Circles

For Teachers 9th - 11th Standards
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...
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...
Worksheet
Curated OER

Circles and Cylinders

For Students 10th
For this geometry lesson, 10th graders break down a circle and identify the different parts. They discuss chords, diameter, radius, circumference, major and minor segment. There are 42 problems broken down into 5 different sections.
Lesson Plan
Dick Blick Art Materials

Start with a Circle...

For Students K - 12th
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...
Worksheet
Curated OER

Circumference of a Circle

For Students 10th
In this circumference of a circle worksheet, 10th graders solve 10 different problems that include various illustrations of circles. First, they multiply pi by the given diameter of the circle. Then, students determine the radius by...
Lesson Plan
Curated OER

Perpendicular Segments in a Circle

For Teachers 9th - 12th Standards
High schoolers explore the concept of circles as they construct a circle using a program such as Cabri Jr. Learners construct a chord and a diameter that are perpendicular, then measure the bisected chord and notice that both sides of...
Interactive
Curated OER

Circle Theorem

For Students 8th - 10th
In this geometry worksheet, students draw an illustration of a circle centered between two points. They draw three line segments. Students answer two questions about the resulting angles. A sample, interactive drawing is included with...
Lesson Plan
Curated OER

Intersecting Lines and Segments of Measures

For Teachers 8th - 12th Standards
Mathematicians measure intersecting lines-and circles, and create chords. In this geometry lesson, students explore interrior and exterior chords created by tangent and secant lines. These segments can be inside the circleor outside the...
Lesson Plan
Curated OER

Identify Polygons: Algebra/Geometry Institute

For Teachers 8th
Eighth graders classify geometric figures.  In this polygon instructional activity, 8th graders identify given geometric figures.  They compare and contrast different polygons.  Students name line segments, identify...
PPT
Curated OER

Circles

For Teachers 3rd - 4th
A very basic presentation on the vocabulary associated with circles has come around. Math whizzes see definitions and examples of the radius, diameter, chord, and central angle of a circle. The last slide says "practice time," but there...
Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
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...
Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
Worksheet
Curated OER

Quiz: Lines and Planes

For Students Higher Ed
In this lines and planes learning exercise, students answer eight true and false questions telling if two line segments are parallel or in the same plane. Students tell the line on the intersection of two lines and name the plane the...
Lesson Plan
Curated OER

Altitudes and Orthocenters: Making Connections to the Nine-Point Circle

For Teachers 9th - 12th
Learners practice various equations for constructing nine-point circles for triangles.
Lesson Plan
Curated OER

Exploring Harmonic Conjugates

For Teachers 9th - 10th
High schoolers investigate harmonic conjugates using Cabri Software or the Ti Calculator to analyze harmonics. They explore different angles measurements as they move their circles around and solve problems.
Worksheet
Curated OER

Construct, Bisect, Duplicate: Geometry Practice with Compass and Straight Edge

For Students 9th - 12th
Geometers employ a straight edge and compass to duplicate and bisect segments and angles, construct perpendiculars, parallel lines, figures, and circles with points of concurrency. Ample practice with 65 questions across 8 worksheets. No...
Worksheet
Curated OER

Quiz: Area of Sector and Segment

For Students 10th - 12th
In this area of sector and segment worksheet, students find the area of a shaded sector. Given the central angle of a segment and the radius, students identify the area of a sector. This one-page worksheet contains ten problems.
Lesson Plan
Virginia Department of Education

Constructions

For Teachers 9th - 11th Standards
Pupils learn the steps for basic constructions using a straightedge, a compass, and a pencil. Pairs develop the skills to copy a segment and an angle, bisect a segment and an angle, and construct parallel and perpendicular lines.
Instructional Video16:21
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Flipped Math

Secants and Tangents

For Students 9th - 12th Standards
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...
Lesson Plan
Curated OER

Introduction to Curve Stitching - Line Designs

For Teachers 3rd - 5th
Students develop their awareness that straight line segments can produce the illusion of a curve and helps them recognize and describe number patterns and geometric fundamentals.