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Worksheet
Curated OER

Area of Triangles and Parallelograms

For Students 9th - 12th
In this area instructional activity, students find the area of 21 triangles and parallelograms. Students find the area of each triangle and parallelogram given a sketch and measurements of the figure.
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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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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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Lesson Plan
1
1
Illustrative Mathematics

Right Triangles Inscribed in Circles II

For Teachers 9th - 10th Standards
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
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Lesson Plan
Curated OER

Amazing Triangles

For Teachers 3rd - 6th
Student scientists investigate triangle structures. In this building lesson plan, students explore how to design triangle braces in the construction of structures in order to build a stronger base.
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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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Worksheet
Curated OER

Visualize Triangles

For Students 4th - 5th
For this finding triangles in parallelograms worksheet, students observe parallelograms, visualize half as congruent to triangles, and choose the triangle that would match each one. Students solve 5 problems.
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Lesson Plan
Curated OER

Triangles

For Teachers 3rd - 5th
This unit enables scholars to apply the rule for area of a triangle (area equals half base times height). They practice multiplication and division strategies as they calculate areas.
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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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Worksheet
Curated OER

Area of Triangle - Problem Solving 16.4

For Students 5th - 6th
In this area of triangles worksheet, students find the area of each triangle in the word problems. Students complete five problems.
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Worksheet
Curated OER

Area of Triangles - Word Problems

For Students 5th - 7th
Here is an area of triangles practice worksheet in which learners sharpen their problem solving skills as they solve six story problems.
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Assessment
Noyce Foundation

Parallelogram

For Teachers 6th - 7th Standards
Parallelograms are pairs of triangles all the way around. Pupils measure to determine the area and perimeter of a parallelogram. They then find the area of the tirangles formed by drawing a diagonal of the parallelogram and compare their...
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Worksheet
Curated OER

Area

For Students 5th - 7th
Learners solve and complete four various types of problems. First, they show on the diagram why the area of a triangle is given by a formula. Then, pupils find the area of each triangle and parallelogram illustrated, They also circle the...
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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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Interactive
Curated OER

Area of Parallelogram and Triangle

For Students 10th
In this geometry learning exercise, 10th graders determine the area of triangles and parallelograms. The one page interactive learning exercise contains ten questions. Answers and hints are included. 
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Worksheet
Curated OER

Understanding Categories of Shapes

For Students K - 3rd
What are these shapes? Scholars match seven shapes to their names: rhombus, sphere, square, cone, circle, triangle, and parallelogram. Although there isn't much to this worksheet, the shapes are nicely colored and it would make a good...
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Worksheet
Curated OER

Transformations

For Students 7th - 10th Standards
In this transformations worksheet, pupils draw the transformations of the triangles and parallelograms in graphs. They complete four drawings.
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Instructional Video16:10
2
2
Flipped Math

Parallelograms and Triangles

For Students 9th - 12th Standards
Expand area problems to incorporate prior knowledge. Pupils begin by reviewing the formulas for finding the area of parallelograms and triangles. The scholars apply previous learning of trigonometric ratios and the Pythagorean Theorem to...
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Lesson Plan
Houghton Mifflin Harcourt

Introducing the Concept: Triangles and Quadrilaterals

For Teachers 5th - 7th Standards
Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...
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Worksheet
Raytheon

Understanding Triangles

For Students 6th - 8th
In this understanding triangles worksheet, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
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Worksheet
Math Mammoth

Triangles 1

For Students 5th - 9th
In this triangles worksheet, students measure and calculate the measurements of eight triangles, their sums and classify the triangles as acute, obtuse or right.
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Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
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Lesson Plan
Curated OER

Parallelograms and Triangles

For Teachers 8th - 11th
In this parallelogram and triangle worksheet, students answer 10 word problems regarding the area and perimeter of triangles and the area of parallelograms.
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Worksheet
Curated OER

Geometric Shapes

For Students 3rd - 5th
In this recognizing characteristics of shapes worksheet, students identify characteristics of quadrilaterals, triangles, and parallelograms and determine which sets fall under the same category. Students solve four problems.