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Lesson Plan
Key Curriculum Press

Properties of Special Parallelograms

For Teachers 9th - 11th Standards
Rhombuses, rectangles and squares are have special properties. In this instructional activity, young geometers investigate and make conjectures about diagonals, angles, and parallel lines of parallelograms. 
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Assessment
Inside Mathematics

Quadrilaterals

For Teachers 9th - 12th Standards
What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...
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Lesson Plan
EngageNY

Construct a Perpendicular Bisector

For Teachers 9th - 10th Standards
How hard can it be to split something in half? Learners investigate how previously learned concepts from angle bisectors can be used to develop ways to construct perpendicular bisectors. The resource also covers constructing a...
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Lesson Plan
EngageNY

Special Lines in Triangles (part 1)

For Students 9th - 10th Standards
Allow your pupils to become the mathematicians! Individuals explore the properties of a midsegment of a triangle through construction and measurement. Once they figure out the properties, learners use them to draw conclusions.
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Worksheet
Curated OER

Review of Geometry I

For Students 7th - 10th
In this review worksheet, students identify the characteristics of intersecting and parallel lines  They explore vertical, supplementary, alternate interior, alternate exterior  and corresponding angles.  This two-page worksheet contains...
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Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
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Lesson Plan
Curated OER

Pyramid Activity

For Teachers 8th - 12th Standards
Pupils explore the concept of pyramids. They determine if two sides of a pyramid are perpendicular using a graphing calculator, then discuss parallel and perpendicular lines and how to determine if two lines are parallel or...
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Lesson Plan
Curated OER

Measuring the Earth

For Teachers 9th - 12th
Students use principles of geometry to measure the circumference of the Earth. In this applied geometry lesson, students use mathematics to determine scientific information. They make measurements, calculate the central angle, and use...
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Worksheet
Curated OER

Tangents, Secants, and Chords

For Students 10th
For this tangents, secants and chords worksheet, 10th graders identify and solve 48 different problems that include using 3 different theorems for defining circles. First, they determine the area of each circle with C as the center and a...
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Lesson Plan
Curated OER

Hands-On Geometry

For Teachers 10th
Tenth graders construct a variety of geometric shapes and designs using a Mira, Clinometer and Geometry Flash Cards. They complete a worksheet.
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Activity
Education Development Center

Proof with Parallelogram Vertices

For Teachers 8th - 10th Standards
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
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Lesson Plan
West Contra Costa Unified School District

Investigating Similar Triangles

For Teachers 9th - 12th
Let your use of the resource be in proportion to its usefulness. Pupils investigate similar triangles by measuring side lengths and considering given angle measures. The results of the investigation help develop generalizations about...
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Worksheet
Curated OER

Equations of Lines Perpendicular and Parallel

For Students 9th - 11th
In this algebra learning exercise, students solve linear equations using one and two steps. They solve systems of equations using substitution and elimination with graphing. There are links for ready made tests and quizzes.
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Lesson Plan
Curated OER

Contructions and Conjectures

For Teachers 10th - 11th
Students make constructions and conjectures. In this geometry lesson, students construct right, acute and obtuse angles using a straight edge and a protractor. They investigate parallel lines and the angles formed by the angles.
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Worksheet
Curated OER

Geometry

For Students 6th - 10th
In this geometry worksheet, students find the sum of angles, label angles, and more. Students complete 6 questions total on this worksheet.
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Lesson Plan
Curated OER

Corresponding Sides and Angles of Similar Triangles

For Teachers 9th - 10th
Students differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
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Worksheet
Curated OER

Special Segments in Triangles

For Students 10th
In this special segments in triangles worksheet, 10th graders solve 6 various types of problems related to determining types of segments found in triangles. First, they find a segment if the line parallel is a median or an altitude....
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Worksheet
Curated OER

Logical Relationship of Postulates & Theorems

For Students 10th - 12th
In this postulates and theorems learning exercise, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram.  They use the concept map to prove theorems...
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Lesson Plan
Curated OER

Constructing Perpendicular Bisectors

For Teachers 10th
Tenth graders investigate parallel lines and the angles formed when cut by a transversal. In this geometry instructional activity, 10th graders construct perpendicular lines and discuss midpoint, segments and perpendicular bisectors....
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Worksheet
Mt. San Antonio Collage

The Trapezoid

For Students 9th - 12th Standards
Enjoy this nicely organized worksheet that puts together multiple problems regarding trapezoid proofs. The resource can be used as a guide that begins with proving properties and ends with solving for measures of line segments.
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Worksheet
Curated OER

The Right Angle

For Students 10th
In this geometry learning exercise, 10th graders determine the answer to a vocabulary questions and then follow the give rules to place the answer in the appropriate place on the crossword grid.   The one page learning exercise contains...
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Lesson Plan
Texas Instruments

Investigating Segments in a Quadrilateral

For Teachers 9th - 12th Standards
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, learners use...
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Unit Plan
Mathematics Vision Project

Module 6: Congruence, Construction, and Proof

For Teachers 8th - 10th Standards
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...
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Unit Plan
Curated OER

Connecting Algebra and Geometry Through Coordinates

For Teachers 9th - 10th Standards
This unit on connecting algebra and geometry covers a number of topics including worksheets on the distance formula, finding the perimeter and area of polynomials, the slope formula, parallel and perpendicular lines, parallelograms,...