Answer:
telephone pole height = 480ft
Explanation:
Assume that the shadow that an object casts is proportional to the height of the object. Then one can form the ratio:
Making the assumption that this ratio is proportional for all objects in this given scenario, then one can say that the ratio of the height of the man and his shadow is equal to the ratio of the height of the telephone pole and its shadow:
(man's height) : (man's shadow) = (pole's height) : ( pole's shadow)
Substitute:
6ft : 4ft 6in = (telephone pole hiehgt) : 30ft
Convert to inches (since it is all in the same unit now, one's doesn't need to write the unit anymore):
72 : 54 = (telephone pole height) : 360
Simplify:
4 : 3 = (telephone pole height) : 360
Now solve, use cross products:
3(telephone pole height) = 1440
Inverse operations,
3(telephone pole height) = 1440
/3 /3
telephone pole height = 480