karivina
Sep 28, 2011, 08:33 PM
A semi circle with diameter 12cm so how to calculate the perimeter
Unknown008
Sep 28, 2011, 11:48 PM
Perimeter = Length of curved surface + Diameter
To get the length of the curved surface, use the formula to get the circumference of a circle and divide the circumference that you get by 2.
matheditor
Sep 29, 2011, 12:45 AM
Perimeter of a circle is called circumference and it is expressed by the formula:
C (circumference)=2*pi*r, where r is the radius of the circle and pi is the pythagorean constant = 3.14...
You want to determine the perimeter of a semicircle, therefore you must divide the circumference by 2:
C = 2*pi*r/2
C = pi*r
Answer: Semi circle circumference = pi*r