Hi Bill,
So the ladder leaning against the wall forms a right triangle
the hypothenuse of the triangle is the ladder and is 10ft
one leg is 6ft and using the pythagorean theorem
102 = 62 + x2
100 - 36 = x2
64 = x2
x = 8
when we move the bottom of the ladder out 3 ft the leg now becomes 9ft
so
102 = 92 + x2
100 - 81 = x2
19 = x2
x = sqrt(19)
so the ladder was 8ft up on the wall and then it moved to sqrt(19)ft up on the wall
so the ladder moved down the wall 8-sqrt(19)
hope this helps
BIll C.
11/25/14