{"id":8887,"date":"2021-12-06T00:03:26","date_gmt":"2021-12-05T18:33:26","guid":{"rendered":"https:\/\/mathemerize.com\/?p=8887"},"modified":"2021-12-07T20:39:29","modified_gmt":"2021-12-07T15:09:29","slug":"formula-for-circumference-of-circle","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/formula-for-circumference-of-circle\/","title":{"rendered":"Formula for Circumference of Circle (Perimeter) – Examples"},"content":{"rendered":"
Here you will learn what is the formula for circumference of circle (perimeter of circle) with examples.<\/p>\n
Let’s begin –<\/p>\n
The perimeter (boundary) of a circle is called its circumference. It is the distance covered by travelling once around circle.<\/p>\n
\nCircumference of circle = \\(2\\pi r\\) <\/p>\n<\/blockquote>\n
where r is the radius of circle.<\/p>\n
And \\(\\pi\\) is an irrational number whose approximate value is \\(22\\over 7\\) or 3.1415….. unless specified, the value of \\(\\pi\\) should be taken as \\(22\\over 7\\)<\/p>\n
<\/p>\n
Circumference (Perimeter) of Semicircle<\/h2>\n
\nPerimeter of Semicircle = \\(\\pi r\\) + 2r = \\(r(\\pi + 2)\\)<\/p>\n<\/blockquote>\n
Rotating Wheels<\/strong><\/h4>\n
\n(i) Distance moved by a wheel in 1 rotation = circumference of the wheel<\/p>\n
(ii) Number of rotations in 1 minute = distance moved in 1 minute\/circumference.<\/p>\n<\/blockquote>\n
Example<\/span><\/strong> : Find the circumference of the wheel of cycle’s whose diameter is 21 cm.<\/p>\n
Solution<\/span><\/strong> : We have, Diameter = 21 cm <\/p>\n
\\(\\implies\\) Radius = \\(21\\over 2\\) = 10.5 cm<\/p>\n
Circumference = \\(2\\pi r\\) = \\(2 \\times {22\\over 7} \\times 10.5\\) = 66 cm<\/p>\n
Hence, the circumference of wheel of cycle is 66 cm<\/p>\n
Example<\/span><\/strong> : If the diameter of a semi-circular plot is 14 m, then find its perimeter.<\/p>\n
Solution<\/span><\/strong> : A semi-circle has been drawn with AB = 14 m as diameter.<\/p>\n
\\(\\therefore\\) Its radius, r = \\(d\\over 2\\) = \\(14\\over 2\\) = 7 m<\/p>\n
\\(\\therefore\\) Perimeter of semi-circle of radius 7 m = \\(\\pi r\\) + 2r = \\({22\\over 7} \\times 7\\) + \\(2\\times 7\\) = 36 m<\/p>\n
Hence, the required perimeter is 36 m.<\/p>\n\n\n