Rangpur Higher Secondary 2011/6

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BdMO
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Rangpur Higher Secondary 2011/6

Unread post by BdMO » Wed Feb 02, 2011 9:06 pm

Problem 6:
2010_rang.png
2010_rang.png (23.15 KiB) Viewed 1300 times
In the figure $AB = 12$ is the diameter of the circle. $MN||AB$ and $\angle BAN = 15^{\circ}$. Find the length of the arc $MN$.

Mehfuj Zahir
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Re: Rangpur Higher Secondary 2011/6

Unread post by Mehfuj Zahir » Wed Feb 02, 2011 11:30 pm

Let the centre is O.Connect O,N.ON=OA.Angle OAN=angleONA=15.AB is parallel to MN.Then angle ANM=15.SO that
angleONM=angleOMN=30.So angleMON=120.Then the length of the arc MN is (120/360).2.pi.6=4pi

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Tahmid Hasan
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Re: Rangpur Higher Secondary 2011/6

Unread post by Tahmid Hasan » Thu Feb 03, 2011 12:28 am

yes it's $4 \pi$
বড় ভালবাসি তোমায়,মা

Dipan
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Re: Rangpur Higher Secondary 2011/6

Unread post by Dipan » Sat Aug 27, 2011 6:27 pm

arc MN is (120/360).2.pi.6=4pi[/quote]

is it a generalized formula????/please explain it.

Dipan
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Re: Rangpur Higher Secondary 2011/6

Unread post by Dipan » Sat Aug 27, 2011 6:29 pm

Mehfuj Zahir wrote:.Then the length of the arc MN is (120/360).2.pi.6=4pi

is it a generalized formula??please someone explain it.

Shifat
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Location: Dhaka, Bangladesh

Re: Rangpur Higher Secondary 2011/6

Unread post by Shifat » Sat Aug 27, 2011 7:13 pm

yes the length of an arc= angle(radian)* radius(9-10 higher math book droshtobbo)

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