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Lesson Plan
EngageNY

Unknown Angle Proofs—Proofs of Known Facts

For Teachers 9th - 10th Standards
Lead the class in a Greek history lesson plan with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete practice...
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Lesson Plan
1
1
Illustrative Mathematics

The Geometry of Letters

For Teachers 3rd - 5th Standards
Use the alphabet as a tool for teaching your class about geometric figures. Break apart capital letters into line segments and arcs. Classify angles as right, acute, or obtuse. Identify parallel and perpendicular lines. An excellent...
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Lesson Plan
Curated OER

Points, Lines, Planes, and Space

For Teachers 9th - 12th
In this points, lines, planes, and space worksheet, high schoolers solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.
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Worksheet
Curated OER

Missing Angle Measures

For Students 5th - 8th
In this missing angle measures instructional activity, students subtract the angle that is given from 180' to find the missing angle measure. Students complete 6 problems.
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Lesson Plan
Curated OER

Angles

For Teachers 3rd - 5th
Learners identify obtuse and acute angles in comparsion to a right angle. They identify obtuse, acute, and right angles. Pupils use "Shape Measure" to construct obtuse, acute, and right angles. They review line segements to locate right...
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Lesson Plan
Curated OER

Dividing Line Segments into n Congruent Parts

For Teachers 9th - 10th
Learners identify lines, and line segments. For this geometry lesson, students divide line segments into equal congruent parts. They complete a laboratory activity dealing with lines and segments.
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Lesson Plan
Curated OER

Lines, Segments, and Rays

For Teachers 5th
Fifth graders use their arm, toothpicks, and marshmallows to create lines, segments, and rays. In this lines, segments, and rays lesson plan, 5th graders learn how these appear on a plane.
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Assessment
Concord Consortium

Short Pappus

For Students 9th - 12th Standards
It's all Greek to me. Scholars work a task that Greeks first formulated for an ancient math challenge. Provided with an angle and a point inside the angle, scholars develop conjectures about what is true about the shortest line segment...
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Worksheet
Curated OER

Angles in Circles

For Students 10th
In this angles in circles activity, 10th graders solve 10 different problems that include tangents and chords and intersecting chords. First, they find x when given 2 intersecting chords. Then, students determine x given the diameter...
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Worksheet
Curated OER

Tangents, Secants, and Chords

For Students 10th
In this tangents, secants and chords activity, 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
West Contra Costa Unified School District

Parallel Lines Cut by a Transversal

For Teachers 9th - 12th
Parallel lines seem so right for each other. It's too bad they'll never, ever meet. Learners use tracing paper to discover relationships among angles formed by two parallel lines cut by a transversal. They apply this information to find...
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Lesson Plan
EngageNY

Unknown Angle Proofs—Proofs with Constructions

For Teachers 9th - 10th Standards
Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...
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Lesson Plan
Virginia Department of Education

Angles, Arcs, and Segments in Circles

For Teachers 9th - 11th Standards
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
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Lesson Plan
2
2
Illustrative Mathematics

Shortest Line Segment from a Point P to a Line L

For Teachers 9th - 11th Standards
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the class...
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Lesson Plan
EngageNY

Similarity and the Angle Bisector Theorem

For Teachers 9th - 10th Standards
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
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Lesson Plan
Curated OER

Lines and Angles

For Teachers 6th
Sixth graders explore lines and angles. They create visual representations of lines, rays and angles by drawing them on paper and using a geoboard. On paper, 6th graders write a summary of the characteristics of their representations.
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Worksheet
Curated OER

Lines and Angles

For Students 6th - 8th
In this math worksheet, students find the information concerning the line segments and angles. They define the complimentary and supplementary angles.
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Worksheet
Curated OER

Points, Lines, Segments, Rays, and Angles

For Students 5th
In this geometry instructional activity, 5th graders label the two figures shown. Worksheet reviews and provides examples of a point, parallel lines, angles, rays, line segments, and perpendicular lines.
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Worksheet
Curated OER

Parallel Lines and Proportional Parts

For Students 10th
In this parallel lines and proportional parts worksheet, 10th graders solve 5 different problems related to determining whether lines are parallel and proportional in each figure. First, they refer to the figure shown at the top to...
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Lesson Plan
Curated OER

Geometry: Lesson 1: Points, Lines, Segments, Angles

For Teachers 4th
Fourth graders examine the concepts of, draw, and label points, lines, segments, and angles, They draw, label, and identify horizontal, vertical, intersecting, parallel, and perpendicular lines. They complete an associated worksheet that...
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Lesson Plan
Curated OER

Perpendicular Bisector of a Line Segment

For Teachers 9th - 12th Standards
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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Lesson Plan
Curated OER

Midpoint of a Segment

For Teachers 9th - 12th Standards
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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Lesson Plan
Curated OER

Lines, Rays, Line Segments, and Planes

For Teachers 9th - 12th
Students are introduced to lines, rays, line segments and planes and study the differences between them. They also practice graphing lines, rays, line segments and planes
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Lesson Plan
Curated OER

Measuring Angles & Segments

For Teachers 10th - 12th
Students view a PowerPoint for a warm-up lesson. They practice measuring around the classroom, measuring such things as the length and width of a desk, pencil, door, and book. Students use a website to practice measuring angles.