GRE
GRE Quantitative Reasoning Section

Finding the Length of a Side in Triangle Using Law of Cosines

Hard Geometry Triangles

In triangle ABC, the lengths of the sides are given as follows: side AC measures 10 units, side AB measures 14 units, and angle A measures 60 degrees. Using the Law of Cosines, which states that for any triangle, $c^2 = a^2 + b^2 - 2ab \cdot \cos(C)$, where $C$ is the angle opposite side $c$, determine the length of side BC (denoted as a).

What is the length of side BC to the nearest tenth of a unit?

Hint

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