Perimeter is the distance around a shape; area is the space it covers. Drag the sliders and watch a rectangle resize live.
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Perimeter is the total distance around the outside of a shape — add up the length of every side. It's measured in units of length, like cm or m.
Perimeter = 4 × side
All four sides are equal.
Perimeter = 2 × (length + width)
Opposite sides are equal.
A rectangle has length 12cm and width 7cm. Perimeter = 2 × (12 + 7) = 2 × 19 = 38cm
Area is the amount of flat space a shape covers, measured in square units like cm² or m². Unlike perimeter, area tells us how much surface is inside the shape, not around it.
Area = side × side
Or side²
Area = length × width
A rectangular garden is 15m long and 8m wide. Area = 15 × 8 = 120 m²
A right triangle has base 10cm and height 6cm. Area = ½ × base × height = ½ × 10 × 6 = 30 cm²
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