Let the given sides be "a" and "b" and the unknown side be "c". The Law of Cosines tells you
.. c^2 = a^2 +b^2 -2ab*cos(C)
.. c^2 = 2^2 +3^2 -2*2*3*cos(60°)
.. c^2 = 7
.. c = √7 ≈ 2.6458
The third side of the triangle is √7, about 2.6458.
.. c^2 = a^2 +b^2 -2ab*cos(C)
.. c^2 = 2^2 +3^2 -2*2*3*cos(60°)
.. c^2 = 7
.. c = √7 ≈ 2.6458
The third side of the triangle is √7, about 2.6458.