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3 votes
A ship leaving dock A has to travel directly to a buoy (represented by point C below) 8.8 miles away. It then may proceed directly to dock B 10.5 miles away. The distance between dock A and dock B is 9.2 miles. What is the measure in degrees of the turn that the ship has to make at the buoy? Round your answer to the nearest tenth of a degree.

1 Answer

4 votes

Answer:

17.7 degree

Explanation:

We can begin by drawing a diagram:

```

C

/|

/ |

/α | 10.5 mi```

A------β------B

\ /

\ /

\/

8.8 mi

```

We can label angles β and α as shown, where β represents the angle from point C to point B and α```

A ------- 9.2 mi -------- B

```

Let's label some angles in the diagram:

- Angle A: the angle between the line from A to C and the line from A to B

- Angle B: the angle between the line from C to A and the line from C to B

- Angle α: the angle at the buoy C

We want to find the measure of angle α. To do that, we can use the law of cosines to find the length of the side opposite angle α:

```

c^2 = a^2 + b^2 - 2ab cos(C)

```

where a = 8.8, b = 10.5, and C = angle B. We can solve for cos(C):

```

cos(C) = (a^2 + b^2 - c^2) / 2ab

```

Since we know a, b, and c (8.8, 10.5, and 9.2 respectively), we can calculate cos(C):

```

cos(C) = (8.8^2 + 10.5^2 - 9.2^2) / (2 * 8.8 * 10.5) ≈ 0.701

```

Now we can find angle B using the inverse cosine function:

```

B = cos^-1(cos(C)) ≈ 45.4°

```

Finally, we can find angle α by subtracting angle A from angle B:

```

α = B - A ≈ 17.7°

```

So the measure of the turn that the ship has to make at the buoy is approximately 17.7 degrees.

answered
User JleruOHeP
by
8.2k points
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