Geometry Help!!

Question

Becky is standing at point . She is  feet  inches tall, and her height is represented by . At a certain point in the day, Becky casts a -foot shadow, represented by . At the same time, a sign post, located at point , casts an -foot shadow, represented by .

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How tall is the sign post (if  represents the height of the post)?

The sign post is ____A_____ feet ____B_____ inches tall.

Answer 1

The angle of the shadow is the same in both cases. This means that the ratio of shadow length to the height of the object is the same

So....

AB / BC = DE / EF

Let's use decimals: 5' 3" is 5.25 feet, so:

5.25 / 6 = DE / 18

DE = 3 * 5.25 = 15.75 (15' 9")