In acute triangle ABC , we know the side lengths AB = sqrt(41) and BC = sqrt(34) and that altitude BD = 5 . What is AC ?
[asy]
size(5cm);
pair A,B,C,D;
A=(0,0);
B=(4,5);
D=(4,0);
C=(7,0);
draw(B--C--A--B--D);
draw(rightanglemark(B,D,A));
label("$A$",A,W);
label("$B$",B,N);
label("$C$",C,E);
label("$D$",D,S);
label("$\sqrt{41}$", (A + B)/2, NW);
label("$\sqrt{34}$", (B + C)/2, NE);
label("$5$", (B + D)/2, E);
[/asy]
