perimetre and area

the continuous line forming the boundary of a closed geometrical figure or the enclosing boundary of a curved geometric figure, especially a circle.

Area is the quantity that expresses the extent of a two-dimensional region, shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object. The area of a shape can be measured by comparing the shape to squares of a fixed size.

SI unit: Square metre

In SI base units: 1 m²

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