Area Builder Game
Build area skills with rectangles, corner cutouts and rectangular courtyards.
Choose Practice or Daily to begin.
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Instructions, device progress and accessibility
Choose Easy, Normal or Hard and select Practice or a daily puzzle based on the UTC date. Enter answers, then select Check answer. Hints and Undo mark a round as assisted. Best scores and progress are stored only in this browser; no account is needed.
Local progress is checked when play begins.
How to play Area Builder
Read the dimensions, identify the full shape and any cutouts, then calculate both area and perimeter. Hard rounds use a rectangular hole, where the interior boundary also contributes to total perimeter.
Worked example
A 10 × 8 rectangle with a 3 × 2 corner removed has area 80 − 6 = 74 square units. The resulting L shape has perimeter 36 units.
Math formulas and key skills
Rectangle area = width × height. Perimeter = 2(width + height). Cutout area is subtracted; a central rectangular hole adds an inner perimeter boundary.
Avoid common mistakes
Do not subtract an interior hole from the perimeter. For a central opening, perimeter includes both outside and inside boundary lengths.
Frequently asked questions
How do you find the area of an L-shaped figure?
Subtract the missing corner rectangle area from the original enclosing rectangle.
Does a hole add to perimeter?
Yes. If perimeter means the entire boundary, both the external and the hole’s interior boundaries count.