Alberta Free Tutoring And Homework Help For Math 20-1

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A rescue helicopter locates two people caught in an avalanche. The angle of elevation from the first perosn to the helicopter is 26.7 degrees, and the angle of the elevation from the second person to the helicopter is 48.9 degrees. IF the distance between the two people is 165m, determine how far both people are from the helicopter.

6 years ago

Answered By Leonardo F

It's a classic trigonometric problem. We need to construct a figure like the one shown below.

The value of angle alpha is 48.9 degrees. Hence, the value of the angle A will be 180 - alpha = 180-48.9=131.1 degrees.

The value of angle gamma is 26.7 degrees. Hence, since the sum of the internal angles of a triangle is always 180 degrees, we have the value of angle B:

B=180-131.1-26.7=22.2 degrees.

We can apply now the sine law to discover the value of y (or the distance between the second person caught in the avalanche and the helicopter):

 $\frac{165}{sin\left(22.2^o\right)}=\frac{y}{sin\left(26.7^o\right)}$165sin(22.2o) =ysin(26.7o)  

Isolating y:

 $y=165\times\frac{sin\left(26.7^o\right)}{sin\left(22.2^o\right)}=196.21\approx196m$y=165×sin(26.7o)sin(22.2o) =196.21196m 

Hence, the second person is aproximately 196 m away from the helicopter in a straight line.

Applying the sine law again to solve for z (or the distance between the first person caught in the avalanche and the helicopter), we have:

 $\frac{165}{sin\left(22.2^o\right)}=\frac{z}{sin\left(131.1^o\right)}$165sin(22.2o) =zsin(131.1o)  

  $z=165\times\frac{sin\left(131.1^o\right)}{sin\left(22.2^o\right)}\approx329m$z=165×sin(131.1o)sin(22.2o) 329m 

Hence, the first person is aproximately 329 m away from the helicopter in a straight line, while the second person is 196 m away fro the helicopter, also in a straight line. 

 

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