Students investigate the area of squares and circles. In this geometry lesson, students calculate the area and probability of simple events. They work on a laptop using Safari.

Students explore circles. For this algebra/geometry lesson, students discover the formula for the area of a circle, as they investigate the ratio of the area of a circle to the radius^2.

Teach how to differentiate between chords and perpendicular bisectors. In this geometry lesson, students relate the properties of chords and circle to solving right triangle. They define what makes two chords congruent in side a circle.

Explore lines tangent to a circle. In this math lesson plan, learners 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...

Consider the relationship between side length and area as an input-output function. Scholars create input-output tables for the area of squares to determine an equation in the first installment of a three-part unit. Ditto for the area of...

Learners write the equation of a circle. In this geometry lesson, students check the solution of a coordinate pair by evaluating them. They graph the circle given the equation and radius.

What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.

Using Cabri Jr. young scholars construct a circle and determine the equation of the circle they drew by finding the center and the radius. Students use the distance formula to derive the equation of their circle.

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...

After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.

In this geometry lesson on cylinders, geometers explore how to find the smallest surface area for a given volume.  They use their knowledge to relate it to the real world by making a model of a livestock tank.

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...

Students investigate the area and circumference of a circle. In this geometry lesson, students estimate and measure the radius, diameter and circumference of a circle. This assignment has an online part that is interactive.

Take a swing at the task. Using their knowledge of polygons and solids, scholars design one hole of a miniature golf course. They calculate areas and perimeters, determine the cost of building the holes, make scale drawings, and create...

Middle and high schoolers investigate all the different places in math that square root is present. In this geometry lesson, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...

Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...

Looking for a fun and creative way to celebrate Pi Day? Then this is the resource for you. From a scavenger hunt and trivia contest to PowerPoint presentations and skills practice worksheets, this collection of materials is a...

Explore the volume of solids with a real-life connection. Learners calculate the volume of a deep-dish slice of pizza to determine its price. They model the slice as a part of a cylinder and create a formula for calculating the cost.

Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...

Learners investigate the properties of circles. In this geometry lesson plan, students calculate the area and perimeter of a triangle. They identify the perimeter and radius length of a circle.

Students construct the circumcenter of a triangle. In this constructing the circumcenter of a triangle instructional activity, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the...

High schoolers investigate properties of the four centers of a triangle and explore a special property of the circumcenter and orthocenter of a triangle. This lesson requires the use of Cabri, Jr.

Student find the area of a sector of a circle. For this geometry lesson, students  define the sector of a circle using a sketch. They find and identify examples of sector in the real world.

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.