Finding the Unknown Side of Safety Signs

Learning Resource Type

Learning Activity

Subject Area

Mathematics

Grade(s)

3

Overview

This learning activity allows students to explain their thinking to find the unknown side of a polygon when the perimeter is given. Students will solve three different problems where the perimeter is given and knowledge of polygon attributes are needed to find the missing sides. This activity can be used as an assessment or an extension activity after students have mastered how to find the perimeter of a polygon. 

Phase

After/Explain/Elaborate
Mathematics (2019) Grade(s): 3

MA19.3.25

Solve real-world problems involving perimeters of polygons, including finding the perimeter given the side lengths and finding an unknown side length of rectangles.

UP:MA19.3.25

Vocabulary

  • Attribute
  • Dimension
  • Perimeter
  • Polygon
  • Two-dimensional

Knowledge

Students know:
  • Measurable attributes of objects, specifically perimeter.
  • Strategies for modeling measurement problems involving perimeter.
  • Strategies for representing and computing perimeter.

Skills

The Students are able to:
  • Solve real-world and mathematical problems involving perimeters of polygons.
  • Find the perimeter of a figure given the side lengths.
  • Find an unknown side length of a polygon given the perimeter and one missing side length.

Understanding

Students understand that:
  • Perimeter is measured in length units and is the distance around a two-dimensional figure.
  • If all the sides of a polygon are equal, then the perimeter can be determined by multiplying one side length by the total number of sides.

Learning Objectives

Students will find the unknown side length of polygons when the perimeter is given. 

Activity Details

  1. The teacher will distribute the Unknown Side of Safety Signs Activity Sheet.
  2. The teacher will explain to the students that they will use the Unknown Side of Safety Signs Activity Sheet to solve for the unknown side of safety signs.
  3. The teacher will remind the students they must find the unknown side when given the perimeter. The students will need to use prior knowledge of polygon attributes. (This activity can be completed independently or with partners.)
  4. At the end of class, the teacher can start a class discussion while taking up the activity sheet for assessment purposes.

Assessment Strategies

The teacher will have the students complete the Unknown Side of Safety Signs Activity Sheet for assessment measures.

Background / Preparation

  • The teacher will need to make copies of the activity sheet prior to the learning activity. 
  • Students will need background knowledge of polygon attributes and how to find the perimeter of a polygon. 
https://docs.google.com/document/d/1gJgU4_u3FvbjasKVGGf5t3eDVPPFvXV3IJt4jIzLiBQ…

Approved Date

Owner (Author)

scarver17
ALSDE LOGO

This site may contain links to other websites or content belonging to or originating from third parties or links to websites and features in banners or other advertising. Such external links are not investigated, monitored, or checked for accuracy, adequacy, validity, reliability, availability, or completeness by us. WE DO NOT WARRANT, ENDORSE, GUARANTEE, OR ASSUME RESPONSIBILITY FOR THE ACCURACY OR RELIABILITY OF ANY INFORMATION OFFERED BY THIRD-PARTY WEBSITES LINKED THROUGH THIS SITE.
Alabama Learning Exchange © 2002-2023 by Alabama State Department of Education is licensed under Attribution-NonCommercial-ShareAlike 4.0 International

Design by Adaptive Theme