Answer:
9.54ft
Explanation:
This problem uses pythagoras theorem as the ladder and the wall make a triangle.
A
B C
Points A, B and C represent this problem. BC is 3ft, AC is 10ft and AB is x, now we sub this information into pythagoras theorem formula
3^2+b^2=10^2
Rearranged this is,
b^2=10^2-3^2
b^2=91
b=
b=9.54
The above is rounded to two decimal places