## Chapter 6 : Trigonometry

### Chapter 6 : Trigonometry

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Posts: 80
Joined: Tue May 07, 2013 10:05 am

### Q1 of Warm Up Exercise

Since the calculator given to us will be simple, how will I figure out that the angle is approximately 73 deg (other than eyeballing a sketch)?

Thanks!
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jfu.green

Posts: 3
Joined: Thu Jun 27, 2019 7:56 am

### Re: Chapter 6 : Trigonometry

Hi jfu.green,

We are given the details that the hypotenuse AB = 7 and side AC = 2. This means cos A = 2/7, which is approximately 0.29.

For cosine angles of 0 degrees to 90 degrees:

cos 0 degrees = sqrt(4) / 2 = 1
cos 30 degrees = sqrt(3) / 2 = 0.87
cos 45 degrees = sqrt(2) / 2 = 0.71
cos 60 degrees = sqrt(1) / 2 = 0.5
cos 90 degrees = 0

From the initial calculation, we are looking for a value of 0.29 and from the chart above, we can see this is between angles of 60 to 90 degrees.

The only answer choice that fits within this range is D. Hope this helps!
sr_vineeth_ruveneco

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Joined: Thu Aug 29, 2013 4:04 pm

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