Given the amount of available data:

The cosine rule can be used in three different ways. The following leads to the simplest calculation:

From cosine rule:

These two each lead to more difficult calculations:

From cosine rule: . Now re-arrange to get a quadratic equation and solve for x using the quadratic formula.

From cosine rule: . Now re-arrange to get a quadratic equation and solve for x using the quadratic formula.

The sine rule can be used in two different ways. Both lead to equally simple calculations:

From sine rule:

From sine rule:

All five applications will lead to the same value of x.