How do you figure permiter of a circle? - Answers

The perimeter of a circle is known as the 'Circumference'.!! The Algebraic Equation for circumference of a circle is ; - C = 2 pi r or C = pi d Were C = circumference pi = 3.14.... ~3.14 ( The circular constant) r = radius (distance from edge to the centre point) d = 2 r = diameter ( the distance in a straight line from one side to the other through the centre point). E.g. If we have a radius (r) of 20 units, then 'd' = 2(20) = 40 Hence C = 3.14 X 40 = 125.6 units. or C = 2 x 3.14 x 20 = 125.6 units. NB for area of a circle the equation is A = pi r^(2) In words, 'Area equals ;pi; multiplied to the radius squared. and the answer is in units squared. (units^(2)). NNB 'pi' note the spelling, is an irrational number, so when given values of 3.14, 3.1416, 3.141592, 22/7 these are only approximations, but are useful for learning.