Introducing the Topic
Let’s explore one of the many uses for angles measured in radians, and that is
determining the area of a sector of a circle.
Calculator Operations
Before using the calculator to solve problems in this chapter, set the calculator
to operate in radians by pressing 2ndF SET UP , touching
B DRG
, and double
touching
2 Rad
. Press 2ndF QUIT to exit the set up screen.
A portion of a curve is called an arc.
When the curve is a circle, a
central angle
is an angle whose vertex is at the
center of the circle. The central angle
is said to intercept, or
subtend
, the arc.
Area of a Circular Sector/TRIGONOMETRY USING THE SHARP EL-9600
47
AREA OF A CIRCULAR SECTOR
Chapter ten