At a certain time of day , a man 6 feet tall casts his shadow 8 feet long . Find the length of shadow cast by a building 45 feet tall , at the same time.

We can solve this by setting up a ratio comparing the height of the building to the height of the man and shadow of the building to the shadow of the man.

hb= height of the building
sb= shadow of the building
hm= height of the man
sm= shadow of the man

hb/sb = hm/sm

sb=x

45ft/x=6ft/8ft

x=(45x8)ft/6ft

x=60ft