Instructions
Read each problem carefully. It is highly recommended to draw a diagram for each scenario to visualize the movements and distances. Use the Pythagorean theorem (a² + b² = c²) to find the unknown distance. For the final answers, round to the specified decimal place where required.
Exercises
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W swims 60 miles north, 30 miles east, 30 miles north, and finally 150 miles west. After all this travel, how far is W from the original starting point?
Show your work here:
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A is 50m east of B and 30m west of C. D is 60m east of C, and 40m east of E. F is 50m north of E and 80m north of G. To the nearest tenth of a meter, how far apart are B and G?
Show your work here:
Answer Key
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Answer: 150 miles
Explanation:
- First, combine the north-south movements and the east-west movements.
- Total Northward movement: 60 miles + 30 miles = 90 miles North.
- Total East-West movement: 30 miles East - 150 miles West = -120 miles, which means 120 miles West.
- This creates a right-angled triangle with the two legs being 90 miles and 120 miles. The distance from the start is the hypotenuse.
- Using the Pythagorean theorem: a² + b² = c²
- 90² + 120² = c²
- 8100 + 14400 = c²
- 22500 = c²
- c = √22500
- c = 150 miles
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Answer: 104.4 m
Explanation:
- Establish a coordinate system, placing point B at the origin (0, 0).
- Determine horizontal (East-West) positions:
- B is at (0, 0).
- A is 50m east of B, so A is at (50, 0).
- C is 30m east of A, so C is at (50 + 30, 0) = (80, 0).
- D is 60m east of C, so D is at (80 + 60, 0) = (140, 0).
- E is 40m west of D, so E is at (140 - 40, 0) = (100, 0).
- Determine vertical (North-South) positions relative to E:
- F is 50m north of E, so F is at (100, 50).
- F is 80m north of G. This means G is 80m south of F. So G's y-coordinate is 50 - 80 = -30. G's x-coordinate is the same as E and F's. So, G is at (100, -30).
- Calculate the distance between B (0, 0) and G (100, -30). This distance is the hypotenuse of a right triangle.
- The horizontal leg (a) is the difference in x-coordinates: 100 - 0 = 100m.
- The vertical leg (b) is the difference in y-coordinates: 0 - (-30) = 30m.
- Using the Pythagorean theorem: 100² + 30² = c²
- 10000 + 900 = c²
- 10900 = c²
- c = √10900 ≈ 104.403...
- Rounding to the nearest tenth, the distance is 104.4 m.