Abuilding 30 feet tall casts a shadow 20 feet long. a person 6 feet tall is walking directly away from the building toward the edge of the building shadow. how far from the building will the person be when the person shadow just begins to emerge from that of the building

  16 feet

Step-by-step explanation:

The shadow is 20/30 = 2/3 the length of the object, so the 6-foot person's shadow will be 4 ft long. It will begin to emerge when the person is 4 feet from the tip of the building's shadow. That distance is ...

  20 ft - 4 ft = 16 ft

from the building.