Math CentralQuandaries & Queries


Question from atolagbe, a student:

the area of a circle is 154cm square. it is divided into three sectors such that two of the sectors are equal in size and the third sector is three times the size of the other two put together. calculate the perimeter of the third sector. take pi=22/7?


I can help get you started. First of all the area of a circle is $\pi \; r^2$ where $r$ is its radius. Your circle has an area of 154 square centimeters so what is its radius?

Since the area of the third sector is 3 times the sum of the areas of the first two sectors if you divide the circle into 4 equal sized sectors then the third sector is made up of 3 of these four sectors and the first two sectors make up the fourth of the 4 sectors.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS