Students investigate nets as they relate to volume and area. In this geometry lesson, students use nets as a visual to deepen their understanding of surface area and volume of objects. They make conjectures about different objects and...

Ninth graders demonstrate application of area, surface, and volume. They apply formulas to a model of the classroom so they can determine the volume and surface area of the classroom.

Students create three-dimension models demonstrating exponents, multiplying and dividing of fractions, and the use of repeating patterns in tessellations, mirror images, and tiling.

Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.

Pupils identify and define intersecting lines and vertical angles. They draw two intersecting lines and measure one pair of vertical angles. Learners will also move a line to change the angles of a figure and describe the changes in the...

Students explore symmetry. In this geometry lesson plan, student identify and define bilateral symmetry, radial symmetry, pentagonal symmetry, hexagonal symmetry, and cubic symmetry. Students construct examples of these types of symmetry...

Students create squares of different sizes on a geoboard. They find and describe a pattern. Students use the pattern to determine the number of squares possible on a 10-by-10 geoboard. They create squares with a horizontal base (and...

Young scholars build a castle to Ravi's design using the cubes. Students then make an original model of a solid object from diagrams which show views from the top, front, side and back. Young scholars describe the reflection of...

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 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...

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...

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...

High Schoolers investigate the perpendicular bisector of a line segment. They use Cabri Jr. to construct the perpendicular bisector of a segment. The dynamics capabilities of Cabri Jr. allow your learners to observe the lengths of the...

Learners revisit midpoint and segments by graphing on the TI or computer. This activity can be done with pencil and paper, but is more interactive if it is done on a TI-navigator.

High schoolers investigate parallel and perpendicular lines. They use Cabri Jr. to construct and explore the relationships between the slopes of parallel and perpendicular lines. The drawing and measurement tools available with Cabri Jr....

High schoolers explore quadrilaterals in this geometry lesson. They will draw a quadrilateral, measure the angles, and find the sum of the measures of the interior angles using Cabri Jr. The interactive capabilities of Cabri Jr. allow...

Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...

Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...

High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...

Pupils explore the midsegment of a triangle in the geometry lesson. They draw and measure the segment joining the midpoints of the two sides of a triangle and compare its length to the length of the third side of the triangle. The...

High schoolers investigate the sum of the measures of the angles of a triangle. They draw a triangle and measure the interior angles. Using Cabri Jr., learners find the sum of the measures of the interior angles. The lesson provides an...

Students examine tessellations and their geometric properties. Students also develop a better understanding of lines, planes, angles, and polygons.

Students explore geometric concepts by working with Tangram Puzzles. For this Tangram challenge lesson, students use problem-solving tasks that involve physical manipulatives. Students select a picture and use all seven pieces...