The length of the shadow of a flagpole was found to be 72 feet. the shadow of a 3 foot picket fence in line with the flagpole was 4 feet. what is the height of the flagpole?

We can solve this problem by simply using ratio and proportion. Let us call the height of the flagpole to be X. Therefore the ratio and proportion would be:

3 ft is to 4 ft and X ft is to 72 ft

3 / 4 = X / 72

X = (3 / 4) * 72

X = 54 ft

The height of the flagpole is 54 ft.