SOLUTION: Please help! In mountain communities, helicopters drop chemical retardants over areas which approximate the shape of an isosceles triangle having a vertex angle of 38 degrees. T

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Question 41495: Please help!
In mountain communities, helicopters drop chemical retardants over areas which approximate the shape of an isosceles triangle having a vertex angle of 38 degrees. The angle is included by two sides, each measuring 20 ft. Find the area covered by the chemical retardant.
Found 2 solutions by Nate, rfadrogane:
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
Think of the tip of the triangle to be Angle-A; the angle to the right of Angle-A is Angle-B, so b=20 and c=20 while Angle-A is 38 degrees.
Use Law-Of-Cosines:
a%5E2+=+b%5E2+%2B+c%5E2+-+2bc%28cos%28A%29%29
a+=+sqrt%2820%5E2+%2B+20%5E2+-+2%2820%29%2820%29%28cos%2838%28pi%29%2F180%29%29%29
a+=+sqrt%28800+-+800%28cos%2838%28pi%29%2F180%29%29%29
a+=+sqrt%28800+-+630.4086029%29
a+=+sqrt%28169.5913971%29
a+=+13.02272618
*This is done using radian-mode on a calculator.

Answer by rfadrogane(214) About Me  (Show Source):
You can put this solution on YOUR website!
Area can be solve by using this formula.
Let A = area of the triangle
x = be the included angle
a = sides of the triangle
^n means raised to the power of 'n'

A = a^2/2 sin x (area for the triangle with the given two sides and an included angle)
= [(20^2)/2] sin 38 deg.
A = 123.132 sq. ft. ---ans