Equable shape

A two-dimensional equable shape (or perfect shape) is one whose area is numerically equal to its perimeter.^[1] For example, a right angled triangle with sides 5, 12 and 13 has area and perimeter both have a unitless numerical value of 30.

^ Bradley, Christopher J. (2005). Challenges in Geometry: For Mathematical Olympians Past and Present. Oxford University Press. p. 15. ISBN 0-19-856692-1.

[1] Bradley, Christopher J. (2005). Challenges in Geometry: For Mathematical Olympians Past and Present. Oxford University Press. p. 15. ISBN 0-19-856692-1.

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