Drawing a diagram may be helpful to solving this problem.
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The relationships between the flagpole and its shadow and the
woman and her shadow can be depicted as a right triangles
because both the flagpole and the woman are perpendicular to
the ground. The problem states that the triangles are similar.
Similar triangles have sides of lengths proportionate to each
other, so a ratio can be set up between the ratio of the flagpole’s
height to the length of its shadow and the woman’s height to
the length of her shadow as such, where x represents the height
of the flagpole in feet:
\(\frac{x}{lenth of shadow}=\frac{height of woman}{length of shadow}\)
\(\frac{x}{6}=\frac{5}{3}\)
\(3x=30\)
\(x=10 \)
The flagpole is 10 feet tall, which is greater than the value in
column B. Therefore the answer is a.