When you work with right triangles, it's convenient to use sine and cosine to ‘scale’ the hypotenuse and give you the lengths of the shorter sides.
This is the simple thought process:
The sketches below illustrate the idea.
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These scaling factors are an immediate consequence of the right triangle definitions of sine and cosine:
![]() Scale the hypotenuse by $\,\cos\theta\,$: |
![]() Scale the hypotenuse by $\,\sin\theta\,$: |
The scaling factors are also an immediate consequence of the
unit circle definitions of sine and cosine.
To get the desired right triangle with hypotenuse $\,h\,$ and acute angle $\,\theta\,,$
start with a
similar right triangle inside the unit circle.
Then, scale it to the correct size, as follows:
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On this exercise, you will not key in your answer. However, you can check to see if your answer is correct. |
PROBLEM TYPES:
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