We can use the Pythagorean Theorem and properties of sines, cosines, and tangents to solve the triangle, that is, to find unknown parts in terms of known parts. Pythagorean theorem: [math]a^2 + b^2 = c^2[/math], Sines: [math]sin A = a/c[/math], [math]sin B = b/c[/math], Cosines: [math]cos A = b/c[/math], [math]cos B = a/c[/math], Tangents: [math]tan A = a/b[/math], [math]tan B = b/a[/math].
Student J. Garces, PreCal 2010