SOLUTION: a triangle has an area of 85 cm2. if two of the sides are 18 and 11 what is the third side?

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Question 963753: a triangle has an area of 85 cm2. if two of the sides are 18 and 11 what is the third side?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
From the area, assume that the base is 18, then,
%281%2F2%2918h=85
h=170%2F18
The angle, A, opposite the unknown side, a, can be determined using side 11 and h since,
sin%28A%29=h%2F11=170%2F198
A=59.158
So then using the law of cosines,
a%5E2=11%5E2%2B18%5E2-2%2811%29%2818%29cos%2859.158%29
a%5E2=121%2B324-203.018
a%5E2=241.982
highlight%28a=15.56%29