Question

If a 30-foot silo casts a 20-foot shadow, what is the approximate measure from the tip of the shadow to the top of the silo?

Answer 1

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Answer:

  (d)  36 feet

Step-by-step explanation:

Use your sense of geometry.

The hypotenuse of a right triangle will never be less than the longest side, and will never be greater than 1.5 times the longest side*.

That means the only reasonable answer choices will be between 30 and 45 feet. There is only one such choice.

The measure is about 36 feet.

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If you like, you can find a more exact value using the Pythagorean theorem. The distance d of interest is ...

  d^2 = 20^2 +30^2 = 1300

  d = √1300 = 10√13 ≈ 36.0555 ≈ 36 . . . feet

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* The longest hypotenuse will be √2 ≈ 1.4142 times the longest right triangle leg when the two legs are equal length.