Question

A 35-foot tall pole is leading towards a building. To stop the pole from leaning further, a 48-foot long cable is secured from the top of the pole to a stake in the ground opposite of the building. If the stake is 30 feet from the pole, what angle does the cable make with the pole?

Round the answer to the nearest tenth.

Answer 1

9514 1404 393

Answer:

38.5°

Explanation:

A triangle solver can give an answer easily. The angle is 38.5°.

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The law of cosines can be written to solve for an unknown angle C opposite side 'c' and flanked by sides 'a' and 'b'.

C = arccos((a² +b² -c²)/(2ab))

Here, we have a=35, b=48, c=30, so the angle is ...

C = arccos((35² +48² -30²)/(2·35·48)) = arccos(2629/3360) ≈ 38.515°

The angle the cable makes with the pole is about 38.5°.