Question 34512
Let the length be x
Let the distance from bottom ... be x-8
Distance = x-1
From pythagorean theorem:

(x-1)^2+(x-8)^2=x^2
(x^2+1-2x)+(x^2-16x+64)=x^2
2x^2-18x+65=x^2
x^2-18x+65=0
Factor x=5 and x=13
Remove the x=5 so that x=13
SO given x= 13 can you solve from there?
Paul.