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...

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.

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...

Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...

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...

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.

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...

Even kindergartners can draw triangles in circles, but the assessment task requires a bit more geometric knowledge. Scholars investigate triangles that have a diameter of a circle as one of its sides. They must consider triangles that...

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,...

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...

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

High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...

Students identify the differentiate the different properties of circles and parallelograms. In this geometry lesson, students calculate the area of each solid and identify the formula. They relate Pi to the circumference of a circle.

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.

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...

Students explore volume and surface area. In this math lesson, students fill boxes with cubes to identify the volume of the boxes. Students discuss area.

Students calculate the are of regular polygons. For this geometry lesson, students create polygons on the computer and move it around to create different shapes. They explore the area of different polygons and how they inter-relate.

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...

Pupils investigate inscribing a circle in a triangle. They use Cabri Jr. to draw a triangle, locate the incenter, and use the distance from the incenter to a side of the triangle to inscribe a circle. The dynamic nature of the geometry...

The objective of this activity is to find the percent of the area of a two squares overlapping. Mathematicians find the ratio of area for the part that overlaps to the rectangle formed. The final answer is a percent as a rate per 100....

Students identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.

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.

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