5. Angles of Elevation and Depression
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Recall that in a 45^(∘)-45^(∘)-90^(∘) triangle the legs are congruent.
23 ft
We are given that Imani needs to determine the height of a tree. She holds a 45^(∘) triangle so that one leg is horizontal and she sights the top of a tree along the hypotenuse. We also know that she stands 6 yards from the tree and her eyes are 5 feet from the ground.
6yd=6*3ft=18ft Let's add this information to our diagram. Notice that a 45^(∘) triangle is a right isosceles triangle. Therefore, the legs of this triangle are congruent.
As we can see, the height of the tree is the sum of 18 and 5. 18+5=23 The height of the tree is 23 feet.