How Do You Solve for the Hypotenuse Using SOH CAH TOA?

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SUMMARY

The discussion centers on solving for the hypotenuse in a right triangle using the sine function, specifically with the angle of 30 degrees. The correct application of the sine function, where sin(30) equals 1/2, leads to the equation sin(30) = O/H. Given that the opposite side (O) is 5, the hypotenuse (H) can be calculated as H = O/sin(30), resulting in H = 10. A common error noted is using a calculator set to radians instead of degrees, which can lead to incorrect results.

PREREQUISITES
  • Understanding of basic trigonometric functions (sine, cosine, tangent)
  • Familiarity with the SOH CAH TOA mnemonic for right triangles
  • Knowledge of the unit circle and angle measures in degrees
  • Ability to use a scientific calculator effectively
NEXT STEPS
  • Study the unit circle to understand sine values for various angles
  • Practice solving for hypotenuse lengths using different angles and side lengths
  • Learn about the differences between radians and degrees in trigonometry
  • Explore advanced trigonometric identities and their applications
USEFUL FOR

Students learning trigonometry, educators teaching geometry, and anyone needing to apply trigonometric functions in practical scenarios.

PreciousJade
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I am very confused with this SOH CAH TOA problem.:confused:
sin30 = O/H
and what do you do when you are looking for Hypoteneuse ,
sin30 = 5/H
Like that, the answer is 10 but i really don't know how i should do this.
I tried sin30/5 and it didn't come out right, so HELP!:confused:
 
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thanks a lot :)
 
The answer is 10. The sin function represents a ratio of sides, for this one, the opposite and hypotenuse post. sin(30) is always one half, regardless of the side lengths. So if the angle is 30 deg, and the opposite side is 5, then the sin function will give you the hypotenuse length because it gives you the ratio of one to the other.

If \sin 30 = \frac{1}{2} [/tex] then you can just say \frac{1}{2} = \frac{5}{H} [/tex]
 
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know the unit circle? know how trig relates to triangles? that's how you should solve this problem, sohcahtoa is a crutch.
 
Do you mean you want to find the hypotenuse?
If so:

sin 30 = O/H
multiply both sides by H to give,
H sin 30 = O
then divide both sides by sin 30 to give
H = O/sin 30

Not sure if that what you meant though?
 
PreciousJade said:
I am very confused with this SOH CAH TOA problem.:confused:
sin30 = O/H
and what do you do when you are looking for Hypoteneuse ,
sin30 = 5/H
Like that, the answer is 10 but i really don't know how i should do this.
I tried sin30/5 and it didn't come out right, so HELP!:confused:
Was your calculator in degrees mode or radians mode?

If your calculator is in radians mode, you found the sine of 30 radians, or about 1719 degrees, which is definitely different than the sine of 30 degrees.(That tends to be the most common mistake)
 

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