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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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Interactive
CK-12 Foundation

Bisectors of Line Segments and Angles: Cut an Angle

For Students 6th - 10th
Explore constructions through an interactive online lesson. Given an example of an angle bisector construction, learners investigate the markings to determine the method used. Challenge questions help solidify the steps. 
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Worksheet
Mt. San Antonio Collage

Isosceles Triangles and Special Line Segments

For Students 9th - 12th Standards
Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...
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Instructional Video17:08
2
2
Flipped Math

Measuring Angles

For Students 9th - 12th Standards
An informative presentation shows pupils how to name and measure angles. Scholars revisit the different types of angles and their definitions and use their knowledge of what an angle bisector is to solve algebraic problems. At the end,...
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Interactive
CK-12 Foundation

Bisectors of Line Segments and Angles: Cut a Line

For Students 9th - 12th
Geometric constructions build relationships —by simply manipulating simple tools. An interactive lesson presents a completed construction of a segment bisector and has learners analyze the important aspects. Ultimately, they should be...
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Lesson Plan
EngageNY

Copy and Bisect an Angle

For Teachers 9th - 10th Standards
More constructions! In this third installment of a 36-part series, learners watch a YouTube video on creating door trim to see how to bisect an angle. They then investigate how to copy an angle by ordering a given list of steps.
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Lesson Plan
EngageNY

Tangent Segments

For Teachers 9th - 12th Standards
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
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Lesson Plan
Curated OER

Altitude, Median, and Angle Bisector of a Triangle

For Teachers 9th - 12th Standards
Learners investigate the special properties of an altitude, a median, and an angle bisector and explore how these special segments divide the area of a triangle. The dynamic nature of Cabri Jr. allows pupils to form and verify conjectures.
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Worksheet
Curated OER

Angle Bisectors

For Students 10th
In this angle bisectors learning exercise, 10th graders solve and complete 12 different problems. First, they find the value of xand the measure of the indicated angles for each situation. Then, students find the values of each indicated...
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Worksheet
Curated OER

Classifying Angles

For Students 10th
In this classifying angles worksheet, 10th graders solve and complete 21 various types of problems. First, they use the diagram shown on the right to answer the questions that follow. Then, students solve for x and find the measure of...
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Assessment
Concord Consortium

Always, Sometimes, Never

For Students 9th - 10th Standards
Do your learners always, sometimes, or never remember the properties of the segments in triangles? Get that number closer to always with a creative lesson analyzing all four segments. Scholars consider a statement about one of the...
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Worksheet
Curated OER

Chapter 5 Final Review Extra Problems. Triangles

For Students 10th - 12th
In this triangles activity, students identify the median, altitude, segment, angle bisector, perpendicular bisector and triangle midsegment of triangles.  They find the perimeter of triangles.  This three-page activity contains 8...
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Worksheet
Curated OER

Points, Lines, and Line Segments - Homework 16.1

For Students 4th - 5th
In this geometry worksheet, students complete a homework assignment in which they name 3 lines and line segments. They write parallel, intersecting, or perpendicular, to describe the relationships between 4 pairs of lines. They draw an...
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Worksheet
Curated OER

Special Segments in Triangles

For Students 10th
In this special segments in triangles worksheet, 10th graders solve 5 different types of triangles. First, they identify and describe the four types of segments associated with triangles. Then, students draw and label a figure that...
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Worksheet
Curated OER

Special Segments in Triangles

For Students 10th
In this special segments in triangles activity, 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. Then,...
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Worksheet
Curated OER

Angle Measurement

For Students 10th
In this angle measurement activity, 10th graders solve 24 different problems related to determining the measurement of various angles. First, they define the various ways to measure an angle and define the type of angle that it is. Then,...
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Worksheet
Curated OER

Angle Measurement 2

For Students 10th
In this angle measurement worksheet, 10th graders solve 24 problems that include determining the measurement of various angles. First, they define each angle and the specific type that is shown in each. Then, students determine the...
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Lesson Plan
Curated OER

Special Segments in a Triangle

For Teachers 10th
For this geometry worksheet, 10th graders review the vocabulary associated with the special segments of a triangle and the associated points of concurrency and solve problems in which they find the indicated missing angle or segment. ...
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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
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
Virginia Department of Education

Constructions

For Teachers 9th - 11th Standards
Pupils learn the steps for basic constructions using a straightedge, a compass, and a pencil. Pairs develop the skills to copy a segment and an angle, bisect a segment and an angle, and construct parallel and perpendicular lines.
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Unit Plan
Curated OER

Transformations in the Coordinate Plane

For Teachers 9th - 12th Standards
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
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Lesson Plan
Curated OER

Special Segments of Triangles Jigsaw Activity

For Teachers 11th - 12th
Students identify the special segments of triangles, the median, angle bisector, altitude, and perpendicular bisectors.
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Assessment
Concord Consortium

Detective Stories

For Students 9th - 12th Standards
The truth will always come out. A short performance task has learners considering a witness statement given to a detective. They apply special line segments in triangles and Ceva's Theorem to prove that the witness is actually lying.