a rectangular area of land is being sold off in smaller pieces. the total area of the land is 2^15 sq. miles. the pieces being sold are 8^3 sq. miles in size. how many pieces of land can be sold at the stated size? compute the actual number of pieces.

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4