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Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
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Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
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Exploring Polygons and The Greedy Triangle
Excellent lesson plan! Anne Linehane's geometry story, The Greedy Triangle, offers an opportunity to practice forming various types of polygons with your learners. Using elastic bands (or Chinese jump ropes),...
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An Introduction to Quadrilaterals
Students explore the concept of quadrilaterals. In this quadrilateral lesson, students play with a floor tile applet to see that there are many types and characteristics of quadrilaterals including parallelograms, trapezoids, rectangles,...
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Quadrilateral Explorations-Grade Nine
Ninth graders investigate quadrilaterals. In this geometry lesson, 9th graders examine and classify quadrilaterals using the slope, midpoint and distance formulas. Additionally, students create various quadrilaterals given three point...
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, high...
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Constructing Quadrilaterals
High schoolers investigate quadrilateral construction in this geometry lesson. They use Cabri Jr. to construct the different quadrilaterals from the quadrilateral hierarchy given minimal definitions. The lesson reinforces the difference...
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Measuring Angles in a Quadrilateral
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...
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Geometry is Fun and EverywhereGeometry, You Don’t Care? Geometry is Fun and Everywhere
Third graders investigate shapes in our world. In this geometry instructional activity, 3rd graders describe plane and solid shapes and identify angles, solid objects and lines of symmetry. Students use online resources, graphic...
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Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Mathematics Vision Project
Module 5: Modeling with Geometry
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 to finding...
Curated OER
The Very Busy Spider
Youngsters explore visual arts by participating in a geometry identification activity. They read the book The Very Busy Spider and identify the techniques spiders use to create webs. Have you ever noticed that their webs are geometric...
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Properties of Special Quadrilaterals
Teach your mathematicians how to identify the properties of quadrilaterals. In this geometry lesson, students solve for missing angles and sides of a special quadrilateral. They use the TI to move the sides around and create different...
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Opposite Angles in a Cyclic Quadrilateral
Learners investigate cyclic quadrilaterals in this geometry lesson. They use Cabri Jr to explore the sum of the measures of opposite angles in a cyclic quadrilateral. The dynamic nature of Cabri allows students to form and verify...
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Quadrilateral Review
Students identify the properties of quadrilaterals. In this geometry lesson, students investigate the history of quadrilaterals and different types of quadrilaterals. They identify the length and mid-segment of each shape.
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An Introduction to Quadrilaterals
Learners explore different types of quadrilaterals. Students define the terminology used with quadrilaterals. They create particular quadrilaterals based on specific characteristics of the quadrilaterals using an online tool.
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Let's Explore the World of Triangles and Quadrilaterals!
Second graders explore the features of triangles and quadrilaterals. In this lesson plan on triangles and quadrilaterals, 2nd graders rotate with their group to five different activities all exploring a different aspect of geometry.
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Geometry Scavenger Hunt
Students hunt for hidden geometric shapes and compare the properties of various shapes. In this geometry lesson, students play a game of finding squares, circles, rectangles, and ovals that have been hidden around the classroom. Students...
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Ptolemy's Theorem
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.
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Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities
When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...
Curated OER
Identify Polygons: Algebra/Geometry Institute
Eighth graders classify geometric figures. In this polygon lesson, 8th graders identify given geometric figures. They compare and contrast different polygons. Students name line segments, identify parallel lines, and interesections. ...
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Quadrilateral within Quadrilaterals
Students investigate the properties of quadrilaterals. In this geometry lesson, students solve problems dealing with construction and designs. They work with quadrilaterals, midpoints and parallelograms.
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Quadrilateral Bunny
Students identify the properties representing quadrilateral. For this geometry lesson, students differentiate between special and regular quadrilaterals. They discuss and demonstrate hierarchy of quadrilaterals.
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Diagonals of Quadrilaterals
Students find the diagonals of the quadrilaterals. In this geometry lesson, students identify and use properties of quadrilaterals. They define different parts of a quadrilateral shape.