Answer:
11.820 ft
Step-by-step explanation:
The mnemonic SOH CAH TOA reminds you that ...
Sin = Opposite/Hypotenuse
The length of the ladder is the hypotenuse of a right triangle with 52° as the base angle. The side opposite is the height up the building where the top of the ladder rests. So, you have the relation ...
sin(52°) = height/(15 ft)
Multiplying by the denominator gives you ...
height = (15 ft)·sin(52°) ≈ 11.820 ft
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You may need to round this number appropriately.