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#1 2007-05-26 05:48:34
- gilligan
- Member
- Registered: 2007-05-26
- Posts: 1
Solving for radius, given chord length and altitude
need help with the formula to determine the radius of a circle if the chord length and altitude from the chord to the point perpendicular to the circumfrence is known
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#2 2007-05-26 06:46:47
- Identity
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- Registered: 2007-04-18
- Posts: 934
Re: Solving for radius, given chord length and altitude
Is this kinda what you mean?
a = Chord length
b = Distance from Midpoint of chord to Centre
r = Radius
By Pythagoras:
Hence,
Last edited by Identity (2007-05-26 06:49:13)
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#3 2007-05-26 07:15:34
- mathsyperson
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- Registered: 2005-06-22
- Posts: 4,900
Re: Solving for radius, given chord length and altitude
I interpreted it like in my diagram.
If that's the case, then the length from the chord to the centre is r-b, and so you have:
Therefore,
Why did the vector cross the road?
It wanted to be normal.
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