<PRE><B>Question 672233</B>
 a ball with a diameter of 20 is partially submerged in a pool full of water so the top of the ball is 5 inches above the surface.
 The intersection of the ball and the waters surface forms a circle, find its circumference.
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A chord (c) on the circle formed in the center of the ball, would be the diameter of the circle on the surface of the water.
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Find the length of half the chord using Pythagoras, mult by 2:
(the radius is the hypotenuse, one side is the center dist to the chord)
 c = 2 * {{{sqrt(10^2 - 5^2)}}}
 c = 17.32 is the chord and the diameter of circle on the surface
therefore
17.32 * pi = 54.4 inches
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