The answer is 21.4 feet. You use the sin of 16 and then divide 5.9 by sin(16)
3a^5 - (-a^5) = 3a^5 + a^5 = 4a^5
6a^7 - 2a^7 = 4a^7
-3a^5 - (-2a^5) = -3a^5 + 2a^5 = -a^5
7a^7 - 8a^7 = -a^7
To find the perimeter of any shape, you find the sum of their side lengths.
In this case, this triangle has side lengths of 1.197, 0.764, and 1.74.
Add these, and the sum is your answer.
1.197 + 0.764 + 1.74 = 3.701
Therefore 3.701 is the correct answer :)