Question

There is a 4-foot fence that surrounds your backyard. The fence casts a shadow that is 5 feet long. If you are 6 feet tall and standing next to the fence, how long will your shadow be?

Answer 1

My shadow would be 7 feet tall.

Since I am standing next to the fence, then whatever difference its actual height and its shadow has, will be the same difference of my shadow to my actual height.

fence: Actual height - 4 ft ; Shadow height - 5 ft; difference - 1 ft
me    : Actual height - 6 ft : Shadow height - ?   ; difference - 1ft

Shadow Height - Actual Height = 1 ft
Sh - 6ft = 1ft
Sh = 1ft + 6ft
Sh = 7ft