How to find side of triangle if two sides and one angle is known?

The Law of Cosines can be used.

If the given angle is opposite one of the given sides, the Law of Sines can be used.

Law of Cosines:
.. c^2 = a^2 +b^2 -2ab*cos(C) . . . . . for any permutation of sides a, b, c, and opposite angle C

Law of Sines:
.. a/sin(A) = b/sin(B) = c/sin(C)

For a 0.25 pfor b o.3pp (0.25+0.3)=0.28