I am not positive but it looks like it is 16 feet because you subtract from the length of the ladder which gives you 18-2 which equals 16
Answer:

Step-by-step explanation:
Recall that the quadratic formula gives you the pattern to follow in order to find the solutions to a quadratic equation of the form: 
It tells us that we need to use the parameters
and
in the following formula in order to get the answers for the x-values that solve it:

so, in our case,
,
, and 
then, replacing these values in the formula, we obtain:

Which looks like the third expression you are listing (although it is a little hard to read)
Answer:
the other sides are 9 and 12
Step-by-step explanation:
use the Pythagorean theorem.
a^{2} +b^{2} =c^{2}
you know that c^2 is 225 because 15*15=225
a^{2} +b^{2} =225
(from here on I just plugged numbers in)
3:4=9:12
9^{2} +12^{2} =225
81+144=225
225=225
Yaaaaay!
(Also can I please have Brainliest? I need it to level up!)