```Question 471143
The span (the total horizontal straight line distance that the structure of the roof crosses between two walls) is given as 30 feet.  The high point of the roof is in the middle of this span and it is 6 feet.
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For this problem, the high point of the roof is assumed to be in the middle of the span.
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Now we're ready to calculate the pitch of the roof. We are told that it is a ratio of the rise (which we know is 6 feet) to half the span of 30 feet. Half the span is 15 feet.
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So the pitch of the roof is the ratio of 6 to 15. This can be written as:
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6:15 (read as "6 to 15") or 6/15
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and this is one form of the answer.
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The ratio can be reduced by dividing both numbers (6 and 15) by 3 to get:
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2:5 (read as "2 to 5") or 2/5
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and this is another form of the answer.
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Those are both correct forms of the answers. However, building framing carpenters would often call this pitch either "6-in-15" or "2-in-5". Also carpenters often don't reduce the fraction so they would be more likely to say "6-in-15" pitch. To a carpenter a "4-in-12" pitch is a common slope for a roof ... 4 inches up for every 12 inches of horizontal span or equivalently 4 feet up for every 12 feet of horizontal span.
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Hope this helps you to understand the problem.```