We have been given that professional plumbers suggest that a sewer pipe should be sloped 0.25 inch for every foot.
Therefore, we can find the slope as:
Therefore, the recommended slope for a sewer pipe is 
<u>Supplementary:</u> 1 and 2 & 3 and 4
Supplementary angles: A pair of angles whose sum is equal to 180°.
<u />
<u>Vertical:</u> 1 and 3 & 2 and 4
Vertical angles: A pair of opposite angles that are made by two intersecting lines.
<u>Complimentary:</u> None
Complimentary angles: A pair of angles whose sum is equal to 90°.
Hope this helps! :D
1.
<span>All three angles are equal and their sum is 180. </span>
<span>3 (3x-12) = 180 </span>
<span>9x -36 = 180 </span>
<span>9x = 180+36 </span>
<span>9x = 216 </span>
<span>x = 216/ 9 = 24 </span>
<span>2. </span>
<span>Area of an equilateral triangle = (sqrt(3)/4 ) s^2 = 270.633 </span>
<span>s^2 = 270.633 / [ sqrt(3) /4] </span>
<span>s^2 = (4)(270.633) / sqrt(3) </span>
<span>s^2 = 625 </span>
<span>s = 25 (side) </span>
<span>Follow the procedure in the link: we don't need the altitude. </span>
<span>r = 25/sqrt(3) =14.43
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