Answer: Approximately 22.62 degrees
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Work Shown:
cos(angle) = adjacent/hypotenuse
cos(y) = 12/13
y = arccos(12/13)
y = 22.6198649
y = 22.62
Notes:
- Arccosine is the same as inverse cosine. On your calculator there should be a button labeled
- Make sure your calculator is in degree mode
- The decimal result for y, shown above, is approximate. I rounded to two decimal places to show the final answer. Round however you need to if your teacher instructs otherwise.