Answer:
not safe
Step-by-step explanation:
The mnemonic SOH CAH TOA reminds you of the relationship between an angle and the ratio of side opposite to hypotenuse:
Sin = Opposite/Hypotenuse
You have the ratio of lengths and you want to find the angle. You use the inverse sine function (arcsin, or sin⁻¹) for this purpose.
sin(angle with ground) = (16.5 ft)/(17 ft) = 33/34
angle with ground = arcsin(33/34) ≈ 76.1°
This angle is greater than the angle of 70° recommended as a maximum. The ladder will not be safe at this height.
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A calculator does all the work. You just need to make sure it is in degrees mode.
