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Lesson Plan
Curated OER

Geometry Journal: Isosceles Triangles

For Teachers 10th - 12th
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
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Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
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Lesson Plan
Curated OER

Isosceles Triangle Theorem

For Teachers 8th - 10th
For this geometry worksheet, learners differentiate between regular triangles and isosceles triangles. They apply the converse theorem and the vertex angle. There are eleven questions with an answer key.
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Lesson Plan
EngageNY

Base Angles of Isosceles Triangles

For Students 9th - 10th Standards
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
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Worksheet
Geometry Accelerated

Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
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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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Lesson Plan
Curated OER

Isosceles Triangle Theorem

For Teachers 8th - 9th
In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.
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Lesson Plan
Curated OER

Geometry Regents Questions: Isosceles Triangle Theorem

For Teachers 9th - 12th
In this isosceles triangle worksheet, students solve 19 multiple choice and short answer problems.  Students use the isosceles triangle theorem to determine unknown angle measures.
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Lesson Plan
2
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Curated OER

Two Triangles' Area

For Teachers 7th - 9th Standards
Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 
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Lesson Plan
Curated OER

Geometric Properties

For Teachers 9th - 12th
Students find triangular angles using the angle theorem. In this geometry lesson, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
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Worksheet
Curated OER

Quiz: Triangle Inequality Theorem

For Students 7th - 8th
In this triangle inequality theorem worksheet, students determine the lengths of the sides of triangles and identify the measure of angles. This one-page worksheet contains ten triangle theorem problems.
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Worksheet
Curated OER

Pythagorean Theorem

For Students 8th - 9th
In this Pythagorean Theorem worksheet, students determine the length of a missing side of triangles. They read story problems, draw diagrams, and use the Pythagorean Theorem to solve real life problems. This one-page worksheet contains...
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Assessment
Inside Mathematics

Rugs

For Teachers 8th Standards
The class braids irrational numbers, Pythagoras, and perimeter together. The mini-assessment requires scholars to use irrational numbers and the Pythagorean Theorem to find perimeters of rugs. The rugs are rectangular, triangular,...
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Lesson Plan
Virginia Department of Education

How Many Triangles?

For Teachers 9th - 11th Standards
Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the same...
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 7th - 10th
Students find the different ratios of a triangle. In this geometry lesson, students use the Pythagorean Theorem to solve for missing sides and angles on a right triangle. They use a robot to create a right triangle.
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 7th - 8th
Young scholars explore the history of Pythagoras and his contributions to mathematics. In this middle school geometry instructional activity, students use one inch tiles to investigate the Pythagorean Theorem and to find the length of...
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 11th
Learners solve problems using the Pythagorean Theorem. For this geometry lesson, students identify the sides and angles of a right triangle. They find the different trigonometric ratios and solve using sine, cosine and tangent.
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Lesson Plan
Curated OER

Perpendicular Bisector Theorem

For Teachers 9th - 12th Standards
High schoolers construct perpendicular bisectors using Cabri Jr. on their graphing calculator. They then construct conditional statements about perpendicular bisectors along with their converse, inverse, and contrapositive.
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Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 8th - 10th
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
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Activity
Curated OER

Inscribing a Square in a Circle

For Teachers 9th - 11th Standards
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 22 different problems related to various types of triangles. First, they name the shortest and longest sides and the smallest and largest angles in each of triangles...
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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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Worksheet
Curated OER

Isosceles Triangles Homework

For Students 9th - 10th
In this geometry instructional activity, students solve isosceles triangles using property of congruency. They find missing angles using the different angle theorem. There are 15 questions.
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Lesson Plan
Curated OER

Geometry and Measurement

For Teachers 6th - 8th
Learners view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Learners use pegboards and string to create more...