Curated OER
Exploring Geometric Mean
Students solve problems using geometric means. In this geometry instructional activity, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.
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Median of a Trapezoid
Learners find the median of trapezoids and other polygons. In this geometry lesson, students identify important properties of trapezoids. They create trapezoids and polygons using Cabri software.
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Constructing Parallel Lines
Students construct parallel lines using a protractor and a straightedge. In this geometry activity, students identify the properties of parallel lines. They use Cabri to graph and observe the lines.
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Secant and Secant Segments
Learners use the secant and secant segment theorem to solve problems. In this calculus instructional activity, students identify where the secant line crosses on a circle. They create circles and secants using cabri software.
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Pythagorean Theorem: Triangles and Their Sides
Students investigate triangles and their relationship to each other. In this geometry lesson, students solve right triangles using the properties of the Pythagorean Theorem. They differentiate between right, acute, straight and oblique...
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Menelaus' Theorem
Students investigate Menelaus Theorem. In this geometry lesson, students calculate the area of polygons. They differentiate between boundaries point, interior points and area of lattice points.
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Pedal Triangles
Pupils identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
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Ceva’s Theorem
Students prove and use Ceva's Theorem to solve problems. In this geometry instructional activity, students analyze polygons for patterns and calculate the area of each shape. They relate polygons to the real world.
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Triangles with Collinear Circumcenters
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.
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Tessellations
Students create tessellations. In this geometry instructional activity, students use polygons to create different patterns by rotation. They identify the reasons for polygons to create the type of tessellation it does.
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SAS Similarity Theorem
Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
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Similar Triangles on the Coordinate Plane
Students investigate triangles and their properties. In this geometry instructional activity, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or...
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Circumscribed Polygons
Students investigate polygons and construct ferris wheels. In this geometry lesson plan, students create a circle and differentiate properties of circles and polygons. They compare the relationship between angles and circumscribed polygons.
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Isosceles Triangles
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
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Pick's Theorem
Students investigate Pick's theorem by completing a lab. In this geometry lesson, students construct polygons using cabri software. They calculate the area of polygons and identify the vertices of each shape.
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Exploring Special Lines
Students compare and order numbers. In this geometry lesson, students write equations for inequalities. They differentiate and apply concepts of triangular properties to solve problems.
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Incenter of a Triangle
Tenth graders find the incenter of a triangle. In this geometry lesson, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
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Constructing Midsegments of Triangles
Pupils construct midsegments. In this geometry instructional activity, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
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Areas of Polygons
Students calculate the are of regular polygons. In 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.
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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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Measuring Angles in a Quadrilateral
High schoolers explore quadrilaterals in this geometry instructional activity. 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...
Curated OER
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...
Texas Instruments
Investigating Segments in a Quadrilateral
Investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral. In this properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral lesson, students use...
Curated OER
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...