Finding the Length of Side BC in Triangle ABC

In triangle ABC, the angle A measures 60 degrees, and the lengths of sides AB and AC are both 5 units. What is the length of side BC?

To find the length of side BC, you can use the Law of Cosines, which states:

$$ c^2 = a^2 + b^2 - 2ab \cos(C) $$

Where:

- $c$ is the side opposite angle $C$ (in this case, side BC),

- $a$ and $b$ are the other two sides (here, both equal to 5 units),

- $C$ is the angle opposite side $c$ (angle A in this triangle, which is 60 degrees).