Question 1121875
<br>
Here is a picture....<br>
{{{drawing(400,400,-10,10,-4,20,line(-9,0,9,0),line(-9,0,0,15.75),line(9,0,0,15.75),line(0,0,0,15.75),line(-135/31,8,135/31,8),locate(-9,0,A),locate(9,0,B),locate(0,17,C),locate(-6,8,D),locate(5,8,E),locate(0,0,O),locate(0.5,8,F),locate(-5,1,9),locate(0.5,4,8)
)}}}<br>
The slope of line AC is 7/4, so we can find the height of the triangle, CO:<br>
{{{7/4 = h/9}}}
{{{h = 63/4}}}<br>
Since OF is 8, CF is 63/4-8 = 31/4.<br>
Then, since triangles CAB and CDE are similar, we can find the length of DE:<br>
{{{(31/4)/x = (63/4)/18}}}
{{{x = 62/7}}}<br>
Answer: the second floor is 62/7 feet wide.