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Sunday, January 5, 2014

Circular Sector Problems

Category: Plane Geometry

"Published in Vacaville, California, USA"

A sector in a circle of radius 25 ft has an area of 125 ft². Find the central angle of the sector.

Solution:

To illustrate the problem, it is better to draw the figure as follows

Photo by Math Principles in Everyday Life

The area of a circular sector is given by the formula


where A is the area of a circular sector, R is the radius of a circular sector, and θ is the central angle of circular sector in radians. Radians is a unit less value of an angle.

Substitute the values of A and R in order to solve for the value of central angle, as follows





You can also express the value of central angle in degrees, as follows



or