Curated OER
Secant and Secant Segments
Students use the secant and secant segment theorem to solve problems. For this calculus lesson, students identify where the secant line crosses on a circle. They create circles and secants using cabri software.
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What is a Tangram?
Students identify a tangram. In this geometry lesson, students read Grandfather Tang's Story and retell each story using the tangrams on a flannel board. Students use tangrams to complete an included worksheet.
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Symmetry
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...
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Applied Science - Science and Math Post-Lab
Students explore optical illusions. In this Applied Science lesson, students view optical illusions and record the data of what they see. Students graph the data that they collect.
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Geoboard Squares
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...
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Modeling Mania
Students describe techniques helpful in solving spatial problems which utilize the notion that a model is a simplified version of something complicated. They utilize methods such as sketching or drawing possible solutions to a problem.
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Midpoint of a Segment
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.
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Exploring the Centroid of a Triangle
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...
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Exploring the Orthocenter of a Triangle
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...
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Investigating Segments in a Right 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...
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Design a Parachute
Students engage in a discussion about what a parachute is and how it works. They create a parachute using different materials that they think will work best. The students test their designs, which will be followed by a class discussion...
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Circumscribing a Circle About a Triangle
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...
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Perpendicular Segments in a Circle
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...
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Perpendicular Bisector of a Line Segment
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...
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Investigating the Slopes of Parallel and Perpendicular Lines
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....
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Inscribing a Circle in a Triangle
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...
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Measuring Angles in a Triangle
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...
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Does the Area of the Quadrilateral Change?
Students study area and quadrilaterals. In this multiplication and area lesson, students use Polystrip models to change rectangles to form different parallelograms. Students find the area of the models use a Geometer Sketchpad to find...
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Angles
Fourth and fifth graders investigate angles and name them according to the criteria for obtuse, acute, and right angles. They examine a human-made yarn pattern on the floor of their classroom and identify angles, vertices, and types of...
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Geo Jammin' - Day 5, Lesson 17: Geo Sakes Alive!
Second graders, given geometric instructions, try to create their own Geo George puppet.
Creative Educator
Dream Room Design
Junior designers brainstorm the elements that a bedroom might have, such as a bed, television, and dresser. They identify which items are needs and which are desires. They practice measurement skills in the classroom by determining its...
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Mobile-ize
Second graders, using a minimum of four space figures, create a mobile. They use a "Draw" program to first plan out their figure.
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Determining Mercantile Volume of a Pine Tree
Fourth graders, acting as foresters, determine timber volumes as sawtimber or pulpwood for marketing. They find the marketable value of a tree using its diameter and volume.
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Surface Area of Pyramids
Pupils identify the surface area of pyramids and other polygons. In this geometry instructional activity, students find the different measurements for the different parts of a polygon. They use the surface area formula to solve for the...