The slope is -4/3 because it's the coefficient of x
Using the Pythagorean theorem:
12^2 + x^2 = 15^2
144 + x^2 = 225
x^2 = 225 - 144
x^2 = 81
x = sqrt(81)
x = 9
The width is 13 ft I hope this helped you!
ST is a midsegment, which tells you that BD=2(ST) or ST=½BD. Use that to substitute the values and find ST.
BD=2(ST)
29+x=2(2x+31)
29+x=4x+62
29=3x+62
-33=3x
x=-11
Now that we know x, we can substitute that into 2x+31 to find ST
ST=2x+31
ST=2(-11)+31
ST=-22+31
ST=9