Question 561513
using similar triangles ___ 4 / 8 = 20 / (d + 8)


"cross" multiplying ___ 4d + 32 = 160 ___ d = 32 ___ this is the starting distance from the lamppost


4 / s = 20 / (31 + s) ___ 4s + 124 = 20s ___ 31 / 4 = s


her shadow decreases 1/4 ft or 3 in