3.MD.8 - About the Math, Learning Targets, and Rigor
Grade 3 Measurement
3.MD.D.8
Full Standard
Solve real-world and mathematical problems involving perimeters of polygons, including finding the perimeter given the side lengths, finding an unknown side length, and exhibiting rectangles with the same perimeter and different areas or with the same area and different perimeters.
Measurement Topic
This standard is reported on the report card in these quarters as follows:
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Report Card Measurement Topic: Demonstrates understanding of measurement, data and geometry. |
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Learning Targets
- Describe a polygon.
- Describe perimeter.
- Find the perimeter of polygons when given the lengths of all sides.
- Find the unknown side lengths of polygons when given the perimeter.
- Explain how rectangles with the same perimeter can have different areas and how rectangles with the same area can have different perimeters.
- Solve perimeter word problems.
About the Math
The perimeter is the distance around a figure or shape. If the shape is a polygon, to find the perimeter, add the length of the sides. Shapes with the same perimeter can have different areas. Shapes with the same area can have different perimeters. Students should be given opportunities to discover the relationship between area and perimeter and what happens when you hold either the area or perimeter constant. Essential vocabulary for this standard includes: area, perimeter, and polygons. Visit the online dictionary Links to an external site. for vocabulary support.
Polygon: a flat, closed shape with sides, no curves
Perimeter: the distance around a shape; the total length of the outer edge around the shape
Area: the covering of a flat surface such as the space within a shape; how many of a chosen unit of area (such as square units) it takes to cover the object without gaps or overlaps
Progression of Standard within Grade 3
This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.
| Quarter 1 | Quarter 2 | Quarter 3 | Quarter 4 |
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Progression of this Standard Across Grades
This progression is informed by the Achieve the Core Coherence Map. Links to an external site. Information is not the complete standard.
| Grade 2 | Grade 4 |
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TASKS
These tasks can be used with small group or whole group instruction.
- Distribute a geoboard to each student. Ask students to create a square with side lengths of 3 units. Ask students to describe what they notice about their shape. "What can you say about the inside of the square?" "How can you describe the outline (where the rubber bands are)?" Ask students to make a rectangle of their choice. Have students turn and talk to a neighbor about their shape (inside and outside). Together generate the definitions of perimeter and area and chart.
- Working with geoboards, tell students that they will be simulating the building of fences to represent perimeter. Show students pictures of fences in the real world and when/how people would use fences. Ask students to make a rectangular yard with a perimeter of 12 units, 8 units and 14 units. Compare representations. "What addition equation could we write to represent the perimeter?" Add these ideas to the anchor chart.
- Distribute color tiles to each student. Discuss how we can build irregular shapes and still find the perimeter. Ask students to build a shape using 8 color tiles that is a polygon, but not a rectangle. Ask students to think about what the perimeter is of the shape they created. Discuss and compare the different shapes and their perimeters. Show the students a 4x2 rectangle with color tiles. "How does the perimeter of the rectangle compare to the perimeter of the irregular shapes?"
- There are 2 shapes with the same area of 15 square units. Their perimeters are very different. What could the shapes be?
- There are 2 shapes with the perimeter of 20 units. Their areas are different. What could the length and width of the shapes be?
- The construction crew was building a playground with a perimeter of 96 feet. The students were trying to figure out what it was going to look like. The playground was not in the shape of a square and the longest side was 32 feet long. What could the playground look like and what could each of the measurements be?
- The sandbox has a perimeter of 90 inches. It is not a square and one of the sides in 15 inches. What could the sandbox look like and what are the measurements of the the sides?
- The perimeter of a rectangular chalkboard is 50 ft. The top of the chalkboard is 17 ft. What are the lengths of the other 3 sides?
- Two shapes each have an area of 24 square units. They each have a different perimeter. What could each perimeter be?
- A farmer is building a fenced in area for the farm animals. He wants to build a space with the largest area he can. The shape of the space needs to be a rectangle. He has enough fence material to create a section with a perimeter of 48 feet. What is the largest area he can make with the material he has. What would the length and width of the space be?
- Tom says that if two figures have different perimeters, they can't have the same area. Do you agree? If not, explain why.
- You are designing a rectangular play pen for your dog. You have 18 yards of fencing. Use the orange Ang Legs to represent 18 yards of fencing. Design different options for your dog's rectangular play pen. Label the different side measurements and record the designs in your notebook.
Slide-Based Tasks
These links are HCPSS created instructional tasks. These tasks are provided in Google slides. These tasks should be used for inspiration and resources, but instruction should start with students having the opportunity to engage with the math first (often involving physical and/or visual models) followed by discussion and explicit instruction to ensure student understanding.
Module 12 • Perimeter and Understanding Area and Basic Facts (3s)
Solve Problems Involving Perimeter:
Module 13 • Area & Perimeter and Basic Facts (6s and All)
Solve Problems Involving Perimeter (and Area):
Additional Tasks
These links provide instructional ideas connected to this standard.
- Polygons, Perimeter and Patterns Links to an external site. (NCTM Illuminations)
- Chairs Around The Table Links to an external site. (NCTM Illuminations)
- Pentomino Perimeters Links to an external site. (Georgia Department of education, pgs. 113-118)
- How Big is a Desk? Links to an external site. (Georgia Department of Education, p. 124)
- A Whole Lot of Garden Hose Links to an external site. (Georgia Department of Education, p. 108 )
- Area and Perimeter Links to an external site. (nrich lesson seed)
- Fencing Extravaganza.doc Download Fencing Extravaganza.doc • 3.MD 8 Fencing Extravaganza.ppt Download 3.MD 8 Fencing Extravaganza.ppt (Cache County, Utah Lesson)
- What's Your Favorite.doc Download What's Your Favorite.doc (Cache County, Utah Lesson)
- My New Bedroom.doc Download My New Bedroom.doc (Cache County, Utah Lesson)
- All Hands on Board.doc Download All Hands on Board.doc (Cache County, Utah Lesson)
- Cowabunga.doc Download Cowabunga.doc (Cache County, Utah Lesson)
- Emily's Quilt Task.pdf Download Emily's Quilt Task.pdf (Cache County, Utah Lesson)
- Flat Stanley.doc Download Flat Stanley.doc (Cache County, Utah Lesson)
- Grandpa's Garden Task.doc Download Grandpa's Garden Task.doc (Cache County, Utah Lesson)
- Zoo Architect.doc Download Zoo Architect.doc (Cache County, Utah Lesson)
- Bunny Task.doc Download Bunny Task.doc (Cache County, Utah Lesson)
- Dog enclosure.doc Download Dog enclosure.doc (Cache County, Utah Lesson)
- Perimeter.doc Download Perimeter.doc (Cache County, Utah Lesson)
- Perimeter Area Task.doc Download Perimeter Area Task.doc (Cache County, Utah Lesson)
Tasks From Print Resources
These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them.
| Book Thumbnail | Book Title | Grade | Pages |
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Teaching Student-Centered Mathematics |
K-3 |
Two-Piece Shapes, Activity 8.8, Page 234 |
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Teaching Student-Centered Mathematics |
3-5 |
Fixed Perimeters, Activity 9.7, Page 265 |
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Hands On Standards (1-2)
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3-4 |
pgs 112-113 (Exploring Perimeter) pgs 114-115 (Measuring Perimeter) pgs 116-117 (Solving Perimeter Problems)
pg 128, (Perimeter of Shapes) pg 130, (Building a Perimeter) |
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Groundworks Reasoning with Geometry (2) |
pages 88-95 (Stretching and Shrinking) | |
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Super Source: Color Tiles K-2 Super Source: Cuisenaire Rods K-2 Super Source: Geoboards K-2 Super Source: Pattern Blocks K-2 Super Source: Color Tiles 3-4 |
3 |
pp 48, 66 p 37 pp 8, 18, 26-29, 42 pp 18-21, 74, 78, 86-89 pp 22-25, 30-33 |
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Roads to Reasoning (1) Roads to Reasoning (2) Roads to Reasoning (3) Roads to Reasoning (4) |
2-3 |
"Toy Hunt", p 55 "Way Around", p 83 pp 52, 67 pp 52, 82 |
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Brain-Compatible Activities for Mathematics 2-3 Brain-Compatible Activities for Mathematics 4-5 |
(102-106)
(99-102) |
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Math In Practice Teaching Third-Grade Math |
3 |
Module 15 |
More Ideas
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Centers
These print resources can be used during independent or center time. These resources could also be used as lesson seeds.
- Find the Perimeter Download Find the Perimeter (HCPSS-adapted resource)
- Perimeters of 18 Download Perimeters of 18 (HCPSS-adapted resource)
Independent Practice/Homework
These resource sheets can be used for independent practice or homework. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.
- Perimeter of Polygons a Links to an external site.
- Perimeter of Polygons b Links to an external site.
- Find the Unknown Side Length When Given the Perimeter Links to an external site.
- Area and Perimeter a Links to an external site.
- Area and Perimeter b Links to an external site.
- Area and Perimeter c Links to an external site.
- Draw and Find Perimeter Links to an external site.
- Draw and Find Perimeter_2 Links to an external site.
- Find Perimeter Links to an external site.
- Find Perimeter_2 Links to an external site.
- Find Perimeter_3 Links to an external site.
- Find Perimeter_4 Links to an external site.
- Find Perimeter_5 Links to an external site.
- Find Perimeter and Area Links to an external site.
- Same Perimeter_Different Areas (performance task) Links to an external site.
- Use Perimeter to Find Unknown Side Length Links to an external site.
- Use Perimeter to Find Unknown Side Length_2 Links to an external site.
- Use Perimeter to Find Unknown Side Length_3 Links to an external site. Links to an external site.
- Use Perimeter to Find Unknown Side Length_4 (performance task) Links to an external site.
- Create Perimeter to Match a Given Area Links to an external site.
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Learning Targets
- Describe a polygon.
- Describe perimeter.
- Find the perimeter of polygons when given the lengths of all sides.
- Find the unknown side lengths of polygons when given the perimeter.
- Explain how rectangles with the same perimeter can have different areas and how rectangles with the same area can have different perimeters.
- Solve perimeter word problems.
Learning targets identify what students should be able to do.The rubric can be applied to tasks and observations for assessment and/or grading.
Rubric for Tasks Links to an external site.
Visit the SBIR (Standards Based Instruction and Reporting) tab in Course Essentials for more information and clarification. There you will find the measurement topic crosswalk, report card comments, links to professional learning/resources and guidance.
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This course content is offered under a CC Attribution Non-Commercial Share Alike
Links to an external site. license. Content in this course can be considered under this license unless otherwise noted.