A chord with a length of 5 5 runs from pi/8 π8 to pi/3 π3 radians on a circle. What is the area of the circle?

1 Answer
Jan 7, 2018

Area of circle color(blue)(A = 190.0334A=190.0334

Explanation:

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Length of chord AB = 5AB=5

AM = (AB)/2 = 5/2AM=AB2=52

Angle subtended by the chord 5 at the center = /_(AOM) = theta(AOM)=θ

Given theta = pi/3 - pi/8 = (5pi)/24θ=π3π8=5π24

/_(AOM) = theta / 2 = (5pi)/48(AOM)=θ2=5π48

In right angle triangle AOM,

OA = r = (AM) / sin ((theta)/2)OA=r=AMsin(θ2)

r = (5/2) / sin ((5pi) / 48) = 5 / (2 * sin ((5pi)/48)) = 7.7775r=52sin(5π48)=52sin(5π48)=7.7775

Area of the circle A_c = pi r^2 = pi * (7.7775)^2Ac=πr2=π(7.7775)2

Area of circle color(blue)(A = 190.0334A=190.0334