Area and Perimeter Flashcards

Grade 3 · Math · Flashcards

Review key vocabulary and formulas for area and perimeter with these study cards.

Flashcards

Perimeter: The total distance around the outside of a shape. Add all side lengths.
Area: The amount of space inside a shape. Measured in square units.
Formula: area of rectangle: Area = Length × Width
Formula: perimeter of rectangle: Perimeter = 2 × Length + 2 × Width (or add all 4 sides)
Formula: area of square: Area = Side × Side
Formula: perimeter of square: Perimeter = 4 × Side
Square centimeter (cm²): A unit of area equal to a square that is 1 cm on each side.
Square inch (in²): A unit of area equal to a square that is 1 inch on each side.
Unit square: A square with a side length of 1 unit, used to measure area by counting.
Rectangle with length 9 and width 4: Area = 36 square units; Perimeter = 26 units
Square with side 6: Area = 36 square units; Perimeter = 24 units
Why label units?: So people know if you measured distance (cm) or surface (cm²). The unit tells what kind of measurement you made.
Same area, different perimeter?: Yes! A 1×16 rectangle and a 4×4 square both have area 16, but perimeters of 34 and 16.