<PRE><B>Question 90068</B>
determine whether the side through the points (2, 3) and (11, 6) is perpendicular to the side through the points(2, 3) and (-3, 18).
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slope of the side thru (2,3), (11,6) is [6-3]/[11-2] = 3/9 = 1/3
slope of the side thru (2,3), (-3,18) is [18-3]/[-3-2] = 15/-5 = -3
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Look at the product of the slopes (1/3)*-3 = -1
Since the product is -1 the sides are perpendicular.
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Cheers,
Stan H.

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