Georgia 3.GSR.8
Georgia Standard (Expectation Cluster)
Determine the perimeter of a polygon presented in real-life, mathematical problems.
Georgia's K-12 Mathematics Standards
Cluster contents
Expectations in This Standard
3.GSR.8 is a Georgia mathematics standard. These are the expectations under it.
- 3.GSR.8.1
Determine the perimeter of a polygon and explain that the perimeter represents the distance around a polygon. Solve problems involving perimeters of polygons.
- 3.GSR.8.2
Investigate and describe how rectangles with the same perimeter can have different areas or how rectangles with the same area can have different perimeters.
Teacher's field guide
What This Cluster Means
What Students Need to Do
- Students find the total distance around a polygon by adding all its side lengths. They solve diagram-based and real-life problems and label answers with the correct unit.
What Mastery Looks Like
- Students add every side length of a polygon accurately and state the answer in linear units. They can explain that perimeter is the total distance around the shape.
Common Misconceptions
- Students may confuse perimeter with area or count squares inside a shape. They may add only the labeled sides, skip a side, or leave off the unit.
How to Assess It
- Exit ticket: A five-sided garden has side lengths 4, 3, 5, 2, and 6 meters. Find its perimeter and show your calculation.
Lesson moves
Ways to Teach It
Give pairs cardboard polygons, rulers, and recording sheets to measure each side and calculate each polygon's perimeter.
Ask students to explain in writing how two different polygons could have the same perimeter.
Use matching cards with polygon diagrams, addition expressions, and perimeters, then have students form complete sets.
Have students measure a bulletin board and calculate how much border trim is needed to go around it.
Free download
Printable 3.GSR.8 Worksheet
A ready-to-print activity worksheet aligned to 3.GSR.8, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
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Related Standards
- 4.GSR.8
Identify and draw geometric objects, classify polygons based on properties, and solve problems involving area and perimeter of rectangular figures.
- 3.GSR.6.1
Identify perpendicular line segments, parallel line segments, and right angles, identify these in polygons, and solve problems involving parallel line segments,...
- 3.GSR.7
Identify area as a measurable attribute of rectangles and determine the area of a rectangle presented in real-life, mathematical problems.
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