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Lesson Plan
Curated OER

Exploring the Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Students construct the circumcenter of a triangle. In this constructing the circumcenter of a triangle lesson, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the triangle. Students...
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Lesson Plan
Curated OER

Exploring the Orthocenter of a Triangle

For Teachers 9th - 12th Standards
Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...
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Lesson Plan
Curated OER

Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
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Worksheet
Curated OER

Intermediate Matching -- Shapes

For Students 3rd - 5th
Students match the following 10 shapes by drawing a line from their names to their pictures: circle, square, rectangle, cylinder, cube, sphere, oval, triangle, octagon and hexagon. This geometry worksheet provides excellent practice for...
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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

Shapes

For Teachers K - 2nd
Students identify attributes of different geometric shapes. In this geometry lesson, students view a  PowerPoint presentation on shapes and use attribute blocks to examine the corners and edges of each shape. Students work together to...
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Worksheet
Curated OER

Triangle Pennies

For Students 10th
In this geometry worksheet, 10th graders arrange pennies in the form of a triangle. They then remove three pennies to rearrange the shape of the triangle and diagram it. An answer key is provided.
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Lesson Plan
Curated OER

Investigating Shapes in Our World

For Teachers 1st
First graders explore shapes. In this geometry lesson, 1st graders make shapes with geo-boards, use play-dough to make three-dimensional figures, and make a shape book using pre-cut shapes.
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Lesson Plan
Curated OER

Shape Recognition

For Teachers Pre-K - K
Students explore geometry by analyzing different shapes. In this shape identification lesson, students discuss the characteristics that make certain shapes unique and the same characteristics that cause shapes to look the same. Students...
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Worksheet
Curated OER

Area and Perimeter of Compound Shapes

For Students 7th - 9th
In this geometry worksheet, students find the area and perimeter of 6 different compound shapes containing squares, rectangles, triangles, and half circles. 
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Worksheet
Curated OER

Area of 2D Shapes Homework

For Students 9th - 12th
For this geometry worksheet, high schoolers solve the area of 2D shapes starting with squares, rectangles, parallelograms, triangles, rhombi, trapezoids, circles, and ending with area of shaded regions. There are 20 questions.
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Handout
El Paso Community College

Geometry Definitions

For Students 7th - 9th Standards
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 
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Worksheet
Curated OER

Geometry Level 3

For Students 7th - 9th Standards
What a wonderful resource! Learners create two-dimensional shapes according to the instructions stated, use the squares to make a triangular prism, a cube, and a pyramid, and identify features of plane shapes, among a myriad of other...
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Worksheet
Curated OER

Naming Geometric Shapes

For Students 5th - 8th
Name that shape! This simple worksheet has learners identify each geometric figure. They examine rectangular prisms, cylinders, rectangular pyramids, and hexagonal prisms. This one-page worksheet contains 8 problems, and the goals seems...
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Lesson Plan
Curated OER

Right Triangles

For Teachers 4th - 8th
Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...
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Interactive
CK-12 Foundation

Identify Accurate Drawings of Triangles: Law of Cosines

For Students 10th - 12th Standards
Drawing triangles is easy, even if you have to calculate the exact length of its sides. Scholars use the Law of Cosines to find missing sides of triangles. An interactive helps them check their answers.
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Lesson Plan
Exploratorium

String Shapes

For Teachers K - 2nd
You'd never have guessed it, but simple pieces of string make a fabulous manipulative for the study of geometry! In the fine lesson plan here, young mathematicians use string to make a variety of polygons. Pupils sit in various...
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Worksheet
Curated OER

Geometry

For Students 2nd - 3rd
In this rectangles and shapes worksheet, students complete a variety of exercises including counting the number of faces on a solid object, coloring solids to match nets and coloring plane shapes. Students check their answers online as...
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Activity
K-5 Math Teaching Resources

Tangram Cutout

For Students K - 5th Standards
Challenge the spatial thinking of your young mathematicians with this printable tangram puzzle. Using different sized triangles, squares, and parallelograms, children must figure out how to fit all the shapes together to create a square.
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PPT
Curated OER

Who Wants to Be a Champion: Perimeter, Area, Symmetry

For Teachers 3rd - 5th
Have your learners practice finding the perimeter and area of geometric shapes using this resource. While just a simple review, this could be a wonderful way to solidify the concepts in their minds.
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Lesson Plan
Alabama Learning Exchange

Polygons-Changing Area Versus Changing Perimeter

For Teachers 5th - 8th Standards
Investigate the area and perimeter of polygons in this geometry lesson. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
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Lesson Plan
Curated OER

Red Circle, Red Circle, What Do You See?

For Teachers K - 1st
Young learners explore shapes and colors. They listen to Brown Bear, Brown Bear What Do You See? by Bill Martin Jr. and use the same language pattern to create a color and shape book of their own. After that, with the leftover magazine...
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Lesson Plan
Curated OER

Exploring Geometric Figures

For Teachers 10th
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain an...
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Lesson Plan
Illustrative Mathematics

Grandfather Tang's Story

For Teachers K - 2nd Standards
It's amazing the complex figures that can be made using only a few simple shapes. Following a class reading of the children's book Grandfather Tang's Story by Ann Tompert, young mathematicians use sets of tangrams to create models of the...