Question 704037
 a 50 foot tower is located on the side of the mountain that is inclined 35 degrees to the horizontal.
 a guy wire is to be attached to the top of the tower and anchored at a point 145 feet downhill from the base of the tower.
 find the shortest length of wire needed.
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This is a side-angle-side problem
The angle opposite the guy wire is made with the tower and the slanting ground
35 + 90 = 125 degrees
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We can use the law of cosines,
c^2 = a^2 + b^2 - 2bc*cos(C) where
a = 145
b = 50
c = guy wire length
C = the angle of 125 degrees
:
c^2 = 145^2 + 50^2 - 2(145*50)*cos(125)
c^2 = 21025 + 2500 - 2(7250)*-.573576
c^2 = 23525 - 14500 * -.573576
c^2 = 23525 - (-88316.86)
c^2 = 23525 + 88316.86
c = {{{sqrt(31841.86)}}}
c = 178.44 ft is the length of the guy wire
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You should check my math here, to confirm this solution