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Deepak

· started a discussion

· 1 Months ago

1/2sinq.xx = 1/2.x/2.root3x
sinq=sin60
q=60
center L 60.
PLZ DO REPLY

Question:

Find the value of the angle subtended by the chord at the centre of the circle, if the length of chord is  3   x and radius is x.

Options:
A)

60º

B)

30º

C)

120º

D)

90º

Solution:

Ans: (c)

  so,  angle on center=120º

Knowledge Expert

· commented

· 1 Months ago

Dear Student
With the help pf pythagorus theorum we can find the value of OB^2={(AO)^2-(AB)^2}
OB^2={X^2-(root3/x)^2}
OB=X/2
NOW, considering the triangle AOB
Taking angle(AOB) as "Theta"
Cos(angleAOB)=BO/AO=(X/2)/(X)=1/2
Cos(AngleAOB)=1/2
AngleAOB=60 degrees
The angle subtended by the chord on the centre of the circle(O) is AngleAOC
AngleAOC=2 X AngleAOB
AngleAOC=2 X 60degrees
AngleAOC=120 degrees
Keep solving, Keep learning
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