Perimeter

In geometry, perimeter is the distance around a flat object. For example, all four sides of a square rhombus have the same length, so a rhombus with side length 2 inches would have a perimeter of 8 inches (2+2+2+2=8).

For a polygon, the perimeter is simply the sum of the length of all of its sides. For a rectangle, the perimeter is twice the sum of its length and width ([math]\displaystyle{ P=2 \ell + 2w }[/math]). Perimeter can also be calculated for other planar figures, such as circle, sector and ellipse.

Real-life objects have perimeters as well. A football field, including the end zones, is 360 feet long and 160 feet wide. This means that the perimeter of the field is 360+160+360+160=1040 feet.

The perimeter of a circle is usually called the circumference. It may be calculated by multiplying the diameter times "Pi". Pi is a constant which is approximately equal to 3.14159; however, the places to the right of the decimal are endless. The number of places used depends on the accuracy required for the result.

Perimeter Media

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  Perimeter is the distance around a two dimensional shape, a measurement of the distance around something; the length of the boundary.

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  cardoid \gamma:[0,2\pi] \to \mathbb{R}^2 (drawing with a=1)x(t) = 2 a \cos(t) (1 + \cos(t))y(t) = 2 a \sin(t) (1 + \cos (t))L = \int_0^{2\pi} \sqrt{x'(t)^2+y'(t)^2}\,\mathrm dt = 16a

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  A depiction of the perimeter of a rectangle. The ℓ (script ell) is the unicode character U+2113. All text is in the en:FreeSans typeface

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  If the diameter of a circle is 1, its circumference equals π.

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  The more one cuts this shape, the lesser the area and the greater the perimeter. The convex hull remains the same.

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  The Neuf-Brisach fortification perimeter is complicated. The shortest path around it is along its convex hull.

Related pages

• Area