Use Crayola Dry Erase Crayons to draw and compare polygons with a partner. What is similar? What is different?
30 to 60 minutes
A polygon is a closed, two-dimensional, geometric figure with at least three straight sides and angles. Triangles, rectangles, and squares are examples of some familiar polygons. Focusing on the attributes of polygons helps to name them. For example, a five-sided polygon is called a pentagon. Regular polygons have sides and angles that are all the same length. Irregular polygons have sides and angles of differing lengths.
Share the definition and examples of polygons with students. Be sure to include examples of regular and irregular polygons. Provide vocabulary for describing the attributes of a polygon (side, angle, vertex, vertices, length of sides, number of sides).
Arrange students in pairs, sitting back-to-back with their dry-erase boards and dry-erase crayons.
Ask each child to draw one polygon on his or her dry-erase board and color it in with a bold dry-erase crayon color.
Partners can now compare their polygons. Ask students to write their ideas either directly on their dry-erase boards or using Crayola Colored Pencils in a math journal or on lined paper. Provide sentence starters:
Our shapes/polygons are similar because...
Our shapes/polygons are different because...
Repeat this learning activity several times, erasing shapes or using the same shapes but comparing them with different partners.
At the end of the lesson invite children to reflect on their learning in a math journal or on lined paper. Provide a reflection prompt, such as “Tell about today’s shape activity.”
LA: Participate in collaborative conversations with diverse partners about grade level topics and texts with peers and adults in small and larger groups.
LA: Ask and answer questions about what a speaker says in order to gather additional information or clarify something that is not understood.
LA: Determine or clarify the meaning of unknown and multiple-meaning words and phrases based on grade level reading and content, choosing flexibly from an array of strategies.
LA: With guidance and support from adults, recall information from experiences or gather information from provided sources to answer a question.
MATH: MA: Reason with shapes and their attributes.
VA: Students will investigate, plan and work through materials and ideas to make works of art and design.
VA: VA: Students experience, analyze and interpret art and other aspects of the visual world.
Introduce the concept of polygons by inviting children to draw any shape they like on an individual dry-erase board using Crayola Dry-Erase Crayons. Arrange some of the children (holding their dry-erase boards) into groups – non-polygons and polygons. Invite the remaining children to determine the characteristics of each group. Repeat this activity, switching the groups the children so all children recognize the difference between polygons and non-polygons.
When drawing polygons with dry-erase crayons on dry-erase boards, demonstrate how to dot the vertices to make them easy to identify and count and slash the sides (put a short line perpendicularly) through each side to count and identify them. Use a different dry-erase crayon color to draw the polygon, dot the vertices, and slash the sides. Students can also be introduced to drawing a curved line to identify and count the angles, again using a different color.
Play other sorting games with polygons drawn on dry-erase boards. Children can hold their boards and move about the room to sort themselves according to number of sides, regular or irregular polygon, polygons that have more or less than 5 sides, etc. Allow children to sort themselves then discuss the attributes they used to put themselves in groups. Provide math vocabulary for children to use to describe their groups.
Share the book If You Were a Polygon (Math Fun) by Marcie Aboff as a read aloud or partner reading experience. Invite each child to draw a polygon then trade with a classmate to turn it into another object.