Find the length of the adjacent

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In summary, the conversation revolved around practicing trigonometry on a math website and encountering difficulty with a specific problem. The problem involved drawing a triangle and finding the length of one of its sides, with the requirement of three significant decimal places. The person found two answers, 4.11cm and 4.10cm, both of which were marked as incorrect on the website. The person then sought clarification on where they may have gone wrong. Another person chimed in and suggested that the website may be looking for an answer with three significant decimal places, specifically 4.109cm. This was confirmed by the use of a calculator, giving the correct answer as 4.109266305cm. The original person expressed gratitude for
  • #1
Gringo123
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I have been practising trig on the bb bitesize maths website. It keeps telling me that I have given the wrong answer to the following problem.
Draw a triangle XYZ with Y being a right angle. The angle at X is 42 degrees and the length of YZ is 3.7cm.
The question requires you to find the length of XY (the adjacent side) to 3 s.f.
I did the calculation tan42 = 3.7/XY and came up with a length of 4.11cm. I also tried 4.10cm (without rounding up), but according to the website both answers are wrong.
Can anyone tell me where I am going wrong?
Thanks
 
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  • #2
It could be that the website is looking for an answer with three significant decimal places, which would be 4.109. My calculator gives the length of the adjacent side as 4.109266305 (cm). To 3 significant figures, this would be 4.11 cm.
 
  • #3
Thanks a lot Mark. As long as I know I did the right calulation I'm happy!
 

1. How do you find the length of the adjacent side in a right triangle?

To find the length of the adjacent side in a right triangle, you can use the trigonometric function cosine, which is equal to the adjacent side divided by the hypotenuse.

2. What is the Pythagorean theorem and how is it related to finding the length of the adjacent side?

The Pythagorean theorem states that in a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the other two sides. This means that if you know the length of the hypotenuse and one of the other sides, you can find the length of the adjacent side by subtracting the square of the known side from the square of the hypotenuse and then taking the square root of the difference.

3. Can you find the length of the adjacent side using only the angle measure and the length of the hypotenuse?

Yes, you can use the trigonometric function cosine to find the length of the adjacent side if you know the angle measure and the length of the hypotenuse. The formula for this is adjacent = hypotenuse * cosine(angle).

4. What is the difference between the adjacent side and the opposite side in a right triangle?

The adjacent side is the side that forms one of the acute angles of the right triangle, while the opposite side is the side that forms the other acute angle. The adjacent side and the opposite side are always perpendicular to each other.

5. Can you find the length of the adjacent side if you only know the length of the opposite side?

No, you cannot find the length of the adjacent side if you only know the length of the opposite side. You need to know either the length of the hypotenuse or the angle measure in order to find the length of the adjacent side.

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