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Area Builder

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PhET Interactive Simulations
University of Colorado Boulder


  • Area
  • Perimeter
  • Fractional areas
  • Scale factors


Create your own shapes using colorful blocks and explore the relationship between perimeter and area. Compare the area and perimeter of two shapes side-by-side. Challenge yourself in the game screen to build shapes or find the area of funky figures. Try to collect lots of stars!

Sample Learning Goals

  • Find the area of a shape by counting unit squares
  • Describe the relationship between area and perimeter
  • Build shapes with a given area and/or perimeter
  • Find the area of an irregular shape by decomposing into smaller, regular shapes (e.g., rectangles, triangles, squares)
  • Determine the scale factor of similar shapes
  • Generalize how area and perimeter change when scaling shapes
Version 1.1.7