Math Problem Statement

A ship starts at point K, travels 180 miles to point L, adjusts its route according to the angle shown, and continues another 203 miles to point M. To the nearest mile, what is the distance from the starting position of the ship to its current position at point M?

Solution

To find the distance from point KK to point MM, we can apply the Cosine Rule in the triangle KLMKLM. The Cosine Rule states:

c2=a2+b22abcos(C)c^2 = a^2 + b^2 - 2ab \cdot \cos(C)

where:

  • cc is the side opposite angle CC,
  • aa and bb are the other two sides,
  • CC is the included angle between sides aa and bb.

In this case:

  • a=180a = 180 miles (from KK to LL),
  • b=203b = 203 miles (from LL to MM),
  • C=107C = 107^\circ (angle at point LL).

Substituting these values into the formula:

KM2=1802+20322×180×203×cos(107)KM^2 = 180^2 + 203^2 - 2 \times 180 \times 203 \times \cos(107^\circ)

First, calculate the values step-by-step:

  1. 1802=32400180^2 = 32400
  2. 2032=41209203^2 = 41209
  3. Calculate cos(107)\cos(107^\circ). Using a calculator, cos(107)0.2924\cos(107^\circ) \approx -0.2924.
  4. Calculate 2×180×203×(0.2924)21249.842 \times 180 \times 203 \times (-0.2924) \approx -21249.84.

Now substitute these values back:

KM2=32400+41209+21249.84KM^2 = 32400 + 41209 + 21249.84 KM294858.84KM^2 \approx 94858.84

Now, taking the square root to find KMKM:

KM94858.84308 milesKM \approx \sqrt{94858.84} \approx 308 \text{ miles}

Thus, the distance from KK to MM is approximately 308 miles.

Would you like further clarification on any step, or have any questions?

Here are some related questions:

  1. How is the Cosine Rule derived and when is it typically applied?
  2. What are some real-life applications of the Cosine Rule?
  3. How would the result change if the angle was different?
  4. Can we solve this problem using any other trigonometric approach?
  5. How does rounding at each step affect the final answer?

Tip: When using trigonometric functions in calculations, keeping the intermediate values as precise as possible can minimize rounding errors in the final answer.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Cosine Rule

Formulas

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

Theorems

Cosine Rule

Suitable Grade Level

High School (Grades 10-12)