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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
Mt. San Antonio Collage

Properties of a Parallelogram

For Students 9th - 12th Standards
More than just a worksheet, the resource provides a thorough guide to navigate through the land of parallelograms. Filled with definitions and theorems, the resource supports learners through problems such as proofs and finding missing...
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Handout
Lockport City School District

Reasons for Geometric Statement/Reason Proofs

For Students 8th - 11th Standards
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 
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Unit Plan
1
1
EngageNY

Congruence, Proof, and Constructions

For Teachers 8th - 10th Standards
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs.  Each of the almost-forty lessons is broken...
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Performance
Radford University

Triangles in Parallelograms

For Teachers 9th - 12th Standards
What's the point of looking at triangles when trying to draw parallelograms? Given three non-collinear points, pupils determine and justify all possible points that would create a parallelogram. They then analyze the four triangles that...
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Unit Plan
Radford University

Quadrilaterals

For Students 9th - 12th Standards
Connect the quadrilaterals. Working in teams, pupils use a variety of tasks to make connections between special quadrilaterals. With the properties well defined, the groups construct quadrilaterals based on those properties. Learners...
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Assessment
Concord Consortium

Rectangulating

For Students 9th - 12th Standards
Use rectangles to find distances. Given a rectangle and three associated triangles, pupils determine the area of the triangles. Scholars know the three triangles have equal areas along with the perimeter of the rectangle and two other...
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Unit Plan
Mathematics Vision Project

Module 3: Geometric Figures

For Teachers 9th - 12th Standards
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
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Activity
Noyce Foundation

The Shape of Things

For Students K - 12th Standards
Investigate the attributes of polygons. A thorough set of lessons presents problem scenarios for elementary through high school classes. The first lessons focus on basic characteristics of polygons, including the line of symmetry. As the...
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Lesson Plan
Virginia Department of Education

Properties of Quadrilaterals

For Teachers 9th - 11th Standards
What type of quadrilateral is that? Discover the difference between the types of quadrilaterals. Small groups investigate types of quadrilaterals using geometry software to find their properties. To keep track of the different...
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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
Mathematics Assessment Project

Evaluating Statements About Length and Area

For Teachers 9th - 12th Standards
Class members complete an assessment task by identifying whether statements about triangles and quadrilaterals are always true, sometimes true, or never true. They then participate in a sorting activity with the same objective.
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Assessment
Mathematics Assessment Project

Floor Pattern

For Students 9th - 11th Standards
You'll never look at floor tiles the same again. An assessment task prompts learners to investigate relationships between patterns involving squares and kites to determine angle measurements. They then prove whether a given quadrilateral...
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Assessment
Mathematics Assessment Project

Circles in Triangles

For Students 9th - 12th Standards
Circles, and triangles, and tangents, oh my! In the assessment task, learners first answer questions leading to the radius of an inscribed circle for a given right triangle. They then use the result to independently determine the radius...
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Handout
Shmoop

Coordinate Proofs

For Students 8th - 11th Standards
How do you know you know? Prove it! The guide goes through several examples and includes a link to a video to teach learners how to work through coordinate proofs. The goal is to prove that different shapes are indeed that shape. 
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Worksheet
Mt. San Antonio Collage

Elementary Geometry

For Students 9th - 12th Standards
Your class may believe that geometry is a trial, but they don't know how right they are. A thorough math lesson combines the laws of logic with the laws of geometry. As high schoolers review the work of historical mathematicians and the...
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Worksheet
1
1
Jesuit High School

Geometry Sample Problems

For Students 8th - 11th Standards
I'd like to prove that this worksheet has a lot to offer. Seven problems using triangles and parallelograms practice the traditional method of a two-column proof. After the worksheet is some practice problems that show worked out...
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Lesson Plan
EngageNY

End-of-Module Assessment Task - Geometry (module 1)

For Students 9th - 10th Standards
Have you hit a wall when trying to create performance task questions? Several open-ended response questions require a deep level of thinking. Topics include triangle congruence, quadrilaterals, special segments, constructions, and...
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Lesson Plan
EngageNY

Review of the Assumptions (part 2)

For Students 9th - 10th Standards
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...
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Lesson Plan
EngageNY

Special Lines in Triangles (part 2)

For Teachers 9th - 10th Standards
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
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Lesson Plan
EngageNY

Review of the Assumptions (part 1)

For Students 9th - 10th Standards
What was the property again? Tired of hearing this from your pupils? Use this table to organize properties studied and as a reference tool for individuals. Learners apply each property in the third column of the table to ensure their...
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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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Lesson Plan
EngageNY

Properties of Parallelograms

For Teachers 9th - 10th Standards
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
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Assessment
Georgia Department of Education

Analytic Geometry Study Guide

For Students 9th - 12th Standards
Are you looking for a comprehensive review that addresses the Common Core standards for geometry? This is it! Instruction and practice problems built specifically for standards are included. The material includes geometry topics from...