Virginia SOL 3.MG.2.b.ii
The Standard
estimate and measure the distance around a polygon (with no more than six sides) to determine the perimeter and justify the measurement
Virginia Standards of Learning for Mathematics · The student will use multiple representations to estimate and solve problems, including those in context, involving area and perimeter (in both U.S. Customary and metric units).
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students estimate the distance around a polygon with up to six sides. They measure every side, add the lengths, label the unit, and explain why the total is reasonable.
What Mastery Looks Like
- Given an irregular polygon, a student chooses a sensible unit, records each side length, and finds the perimeter accurately. The student compares the answer with an estimate and uses labeled measurements or an addition equation to justify it.
Common Misconceptions
- Students may find area instead, measure only one side, or add only the labeled sides. They may mix units, count corner points, or forget to include units.
How to Assess It
- Give each student a printed irregular pentagon and a centimeter ruler. Ask: “Estimate its perimeter, measure every side, write an addition equation, and explain whether your answer is reasonable.”
Lesson moves
Ways to Teach It
Make polygons with four to six craft sticks, then have students estimate and measure each perimeter in inches or centimeters.
Ask, “Maya measured four sides of a pentagon. What is missing, and how would it affect her perimeter?”
Run a perimeter card sort where students match polygon diagrams, side length lists, addition equations, and totals.
Mark a five-sided garden outline with string, then estimate and measure how much edging would go around it.
Free download
Printable 3.MG.2.b.ii Worksheet
A ready-to-print activity worksheet aligned to 3.MG.2.b.ii, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- 6.MG.4.d
Determine whether polygons are congruent or noncongruent according to the measures of their sides and angles.
- 4.MG.5.e
Denote properties of quadrilaterals and identify parallel sides, congruent sides, and right angles by using geometric markings.
- 3.MG.2.a.ii
estimate and determine the area of a given surface by counting the number of square units, describe the measurement (using the number and unit) and justify the ...
- 3.MG.2.b.iii
given the lengths of all sides of a polygon (with no more than six sides), determine its perimeter and justify the measurement.
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.