Curated OER
Investigating the properties of a circle
Students use wax paper to look at different properties of circles such as chords, tangent lines, inscribed angles, and inscribed angles in a semi-circle, as well as finding the center of the circle, and use GSP to investigate cyclic...
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Curated OER
Circle Packing
Students identify different parts and properties of circles. In this geometry lesson, students identify the radius, diameter, semicircle and inscribed angle of a circle. They identify the tangent lines to a circle.
Curated OER
Circle Conjectures
Students are given diagrams and are asked to make a conjecture. In this geometry lesson, students make conjectures of circles. They complete a lab activity to reinforce making conjectures. The first activity addresses a common core...
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...
Texas Instruments
Cabri Jr. Inscribed and Central Angles
Learners will differentiate between inscribed and central angles in this geometry lesson plan. They answer questions dealing with circles as they relate to inscribed triangles and angles. This assignment includes a printable worksheet.
Curated OER
Around The Stop Sign
Students analyze a drawing of a regular octagon inscribed in a circle to determine angle measures, using knowledge of properties of regular polygons and the sums of angles in various polygons to help solve the problem. They use...
Curated OER
Relationships Among Arc and Angle Measures in Circles
Students follow the directions on the attached worksheet to construct shapes using Geometer's Sketchpad. To start the instructional activity, it is suggested that the teacher guide the students through the initial problem. When...
Curated OER
Properties of Arcs, Lengths and Chords
Students differentiate between the different properties of arcs, arc lengths, chords, and chord lengths. For this circles lesson, students calculate the arc length of a given circle, and find the measure of the inscribed angles of a...
Curated OER
Solving Intercepted Arcs
Students investigate circles and its arcs. In this geometry lesson, students identify the relationship between an circle and its intercepted arcs. THey identify the central and inscribed angles.
Curated OER
Inscribed Quadrilaterals and Parallelograms
Learners differentiate between inscribed quadrilaterals and parallelograms. In this geometry lesson, students identify the shaped of the polygons when it is inscribed inside of a circle. They calculate the missing angles of the inscribed...
Curated OER
Solving Problems Involving Chords, Radii, Tangents, Secants and Arcs within the Same Circle
Tenth graders apply their knowledge of angles related to a circle, radii, secants, tangents and chords of a circle. They practice using formulas related to a circle. They also apply what has been practiced to real life situations.
Curated OER
Incenter of a Triangle
Tenth graders find the incenter of a triangle. In this geometry instructional activity, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
Curated OER
Connecting Area Formulas Produces a Beautiful Formula
In this math worksheet, students find the area of the triangle using the formula of 1/2 bh. Then they find the area using an alternative method.
Curated OER
Plain Figures and Measuring Figures
Students investigate basic geometric concepts. In this geometry activity, students explore solids through measuring and modeling. This assignment models the importance of understanding concrete objects in geometry.
Curated OER
Putting the 'pi' in Pumpkin Pie
Students use geometric formulas to divide a pumpkin pie. In this geometric formulas lesson, students review equations for area and circumference of a circle and divide a pumpkin pie to practice the formulas. Students use the Pythagorean...
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...
Curated OER
Plain Figures And Measuring Figures
Seventh graders investigate the mathematical concept of a sector. They apply the concept to an example problem and then move into a more complex application. They find the area of the side of a cone. This is done as students calculate...
Curated OER
Exploring Centers of a Triangle: Part 1
Students use problem solving skills, formal geometry, and The Geometer?s Sketchpad. They model and solve two real-world problems by constructing the in center and circumcenter of triangles.