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.

Not all structures take the shape of a polygon. The 21st lesson plan in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite...

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.

Students explore circles. In this algebra/geometry instructional activity, 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.

Going around in circles trying to find a resource on sectors of circles? Here is an activity where pupils first complete an assessment task to determine the areas and perimeters of sectors of circles. They then participate in an...

How do the area and perimeters of circles and squares compare? A clever video illustrates the change in the area of a circle and square while their total perimeter stays the same. The task is for learners to predict the point where the...

This activity is a follow-on activity to inscribing a square in a circle. The overall problem is more complex. It deals with geometric constructions, properties of triangles, and regular hexagons. The final part of the activity...

Students analyze relationship between the increase in polygons sides and a circle. In this geometry lesson plan, students relate the size of the central angle of a polygon, to a circle. They compare the formula for the area of a polygon...

Through the use of Internet, video, and hands-on activities, youngsters learn the parts and characteristics of a circle. This fantastic lesson has some excellent website activities included in the plan. Your kids will have a much greater...

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...

Pack the lesson into your plans. Young mathematicians learn about packing and optimization with the context of circular paving stones. They use coins to model the paving stones, and then apply knowledge of circles and polygons to...

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.

Math whizzes use the area probability applet to manipulate the size of the circle and the rectangle to explore the probability that a point in the rectangle is also in the circle.

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...

It's all about the portion size! Given a photo of a pumpkin pie, learners work to determine the number of calories that are missing. Supplemental information provides the angle of the piece that is missing as well as the nutritional...

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.

Explore Apple's spaceship office building. Built in the shape of a circle, the office building offers a unique floor plan challenge. Young scholars use the dimensions of the building to estimate the square footage for each employee. 

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

Explore methods for finding the volume of different three-dimensional figures. The 20th lesson in the 25-part series asks learners to interpret diagrams of 3-D figures and use formulas to determine volume. Scholars must use the...

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

Young scholars measure the perimeter and area of their polygons. In this geometry lesson, students calculate the volume and area using the correct tools. They calculate the time and temperature and the perimeter and side lengths of...

Using Cabri Jr. high schoolers 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.

Students explore different size circles to discover the relationship between diameter and circumference. In this circles and Pi lesson, students construct simple parachutes using circle patterns of varying sizes. Students predict the...

Students investigate the structure of the atom and its composition. In this atom structure lesson, students find the area of cut out circles and drop pens into the circles. They count the number of marks in the circles and relate their...