What is the central angle?
Favorites|Homepage
Subscriptions | sitemap
HOME > Mathematics > What is the central angle?

What is the central angle?

[From: ] [author: ] [Date: 11-10-20] [Hit: ]
72θ = 188.θ = 188.θ = 2.θ = 188.188.2.......
The area of a sector of a circle of radius 12cm is 188.5cm^2. Find the central angle contained in the sector in: a) radians b) degrees.
I cannot get their answers which are 2.618 rads and 150 degrees. I used the area of a sector formula A = 1/2r^2theta, substituted the values I have in and rearranged but I get 116.5 and can't work out where I'm going wrong.
Please explain :)

-
1/2 r² θ = A
1/2 * 144 θ = 188.5
72θ = 188.5
θ = 188.5/72
θ = 2.618 radians

θ = 188.5/72 * 180/π
θ = 150 degrees

Mαthmφm

-
A = 1/2r^2theta
188.5 = (1/2)(144)theta
377 = 144theta
2.618 = theta

to convert to degrees multipy 360 degrees & divide by 2*pi
1
keywords: central,the,What,angle,is,What is the central angle?
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .