Jenna is flying a kite on a very windy day, The kite string makes a 60 angle with the ground. The kite is directly above the sandbox, which is 28 feet away from where Jenna is standing. Approximately how much of the kite string is currently being used?

1 Answer
Dec 18, 2016

The length of Kite string in use is 56 feet

Explanation:

Let the length of the string be #L#

If you are not sure where to start on a problem you could always draw a rough sketch (if appropriate).
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This is the mnemonic I use for the trig ratios

It sounds like

Sew Car Tower and is written as

#"Soh"->sin = ("opposite")/("hypotenuse")#

#"Cah"->cos =("adjacent")/("hypotenuse")#

#"Toa"->tan=("opposite")/("adjacent")#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Our triangle has adjacent and hypotenuse so we use the cosine

#cos(60^0)=("adjacent")/("hypotenuse") -> 28/L#

multiply both sides by #L#

#Lcos(60^0)=L/Lxx28#

But #L/L=1# giving:

#Lcos(60^0)=28#

Divide both sides by #cos(60^0)#

#L=28/cos(60^0)#

#L=56#

But we are measuring feet so we write

The length of Kite string in use is 56 feet