Identifying 2D Shapes

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Objective

SWBAT identify triangles, quadrilaterals, pentagons, hexagons, octagons, angles, and parallel sides.

Big Idea

The Common Core standard is that students will be able to recognize shapes based on attributes such as the number of angles, faces and vertexes.

Teaching the Lesson

25 minutes

Today I made a powerpoint about shapes, angles and line segments to share with students.Identifying Shapes I put up the power point and presented each slide. Looking at the slides, we examine the images to "discover" attributes. This creates the context for the vocabulary, parallel lines, corners, sides, vertices, angles, tri(3), quad(4). With each word or phrase, we return to looking at shape attributes to see if we can "find" more examples that meet the definition.

Depending on student understanding, I draw examples to clarify the terms that students were not clear on. Context is critical in the development of vocabulary, particularly mathematical terms. 

Independent Practice

15 minutes

In this part of the lesson, I ask students to draw a table with 5 columns (which I model) and head the columns with the terms triangle, square, rectangle, trapezoid, and pentagon.  I tell students they have 10 minutes to find as many of each shape as they can. Students tour the classroom and record the shapes they find, placing the object under its proper heading such as table under rectangle. There are labels on many items in the room to help students with this task. I also help students by saying that they may draw a picture of the item and just put its beginning sound if they are not sure how to spell the word. I remind students to look carefully at the shapes and attend to what makes each shape special as they decide which objects are made from which shapes (MP6).

While Common Core standards do not specifically require students to identify shapes, they do expect that students can identify the attributes of shapes. If students recognize a rectangle in a bookshelf, or a trapezoid in a table shape, they are looking for attributes to determine which shape it is. They are constructing a variable argument for why the objects they have chosen represent the shape they are looking for (MP3) when they explain their choices to the class. 

Closing

10 minutes

I ask students to share some of the objects they found in the room.

Which shapes did you find the most? The least?  

I then ask students to share the objects that match the more difficult shapes to identify. I hope that students will use the attributes of the shapes to recognize them in everyday classroom objects.