Subscribe

3rd grade · Math · Unit 11 of 18

Area & Perimeter

Around and inside shapes

What your child practices

Finding the perimeter (distance around) of rectangles and triangles, finding a missing side, and measuring area in square centimeters and square meters.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 3.6(C); 3.7(B) · area of rectangles as rows times columns, and perimeter and missing side lengths

How we explain it

Children can open this short lesson before they practice.

  1. Perimeter is the distance around a shape. Add all sides.
  2. Area is the space inside. Count the square units.
  3. Perimeter uses cm. Area uses square cm.

Example: A rectangle is 5 cm long and 3 cm wide. What is its perimeter? Add all four sides: 5 + 3 + 5 + 3. That is 16 cm. Answer: 16 cm

Area & Perimeter in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 11 of 18 in 3rd grade Math, after Halves & Fourths of an Inch and before Sorting Polygons.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Each square is 1 square centimeter. What is the area, in square centimeters?

    • 18
    • 16
    • 15

  2. Question 2

    Which rectangle has the same area as a 4 by 4 rectangle?

    • 2 by 9
    • 5 by 4
    • 2 by 8

  3. Question 3

    Which unit is best for the area of a postage stamp?

    • square meters
    • centimeters
    • square centimeters

  4. Question 4

    A rectangle is 8 cm long and 3 cm wide. What is its perimeter in centimeters?

    • 22
    • 28
    • 25

  5. Question 5

    A triangle has sides of 9 cm, 3 cm and 8 cm. What is its perimeter in centimeters?

    answer box

  6. Question 6

    A rectangle is 10 cm long and 3 cm wide. What is its area, in square centimeters?

    • 24
    • 26
    • 30

More 3rd grade