The length of AB of the triangle is 13 units.
How to find the side of a triangle?
The side AB of the triangle can be found using cosine law,
Therefore,
c² = a² + b² - 2ab cos C
c² = 7² + 8² - 2 × 7 × 8 cos 120
c² = 49 + 64 - 112 cos 120
c²= 113 - (-56)
c² = 113 + 56
c² = 169
c = √169
c = 13 units
Therefore, the value of AB is 13 units
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