In ADEF, the measure of ZF=90°, the measure of ZD=62°, and FD = 3.5 feet. Find the length of DE to the nearest tenth of a foot.

so, converting firstly the mixed fractions to improper fractions and then "adding".

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q