The ladder is placed 6 feet away from the wall
The formula you have to use is a2 + b2= c2
[tex] {15}^{2} + 6 {}^{2} = x {}^{2} [/tex]
(I used x instead of c)
225+36=x2
Add them
261=x2
Now find square root
Square root of x2=x
Square root of 261= 6.15549...
x=6.15549
The ladder can reach x feet