Answer: 9 meters
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Work Shown:
- side a = 8
- side b = 5
- angle C = 88 degrees
Applying the law of cosines
c^2 = a^2 + b^2 - 2*a*b*cos(C)
c^2 = 8^2 + 5^2 - 2*8*5*cos(88)
c^2 = 64 + 25 - 80*cos(88)
c^2 = 86.2080403
c = sqrt(86.2080403)
c = 9.2848285
c = 9
Technically he needs 10 meters of rope because of the extra 0.28 portion, but I'll stick with 9 meters since your teacher said to round to the nearest whole number.