Analysis: Take point A as AM⊥BF at point M and point F as FN⊥AB at point N, respectively, use Pythagorean theorem to find the length of BN, and then use similar triangles's judgment and properties to get it.

Answer:

Solution: a is AM⊥BF of point m, and f is FN⊥AB of point n,

AD = 24cm, then BF=24cm,

∴bn=√(bf^2+fn^2)=√(25^2-24^2)=7(cm)，

∠∠AMB =∠FNB = 90, ∠ Anti-missile =∠FBN,

∴△BNF∽△BMA，

∴AB/BF=FN/AM，

∴80/25=AM/24，

Then: AM=( 16×24)/5=(384/5),

So the distance from point A to the ground is: (384/5)+4 = 404/5 (m).

So the answer is 404/5.