## Algebra and Trigonometry 10th Edition

c = 11.06 A = $51.79^{o}$ B = $23.21^{o}$
Note: The Standard Form of the Law of Cosines is: $a^{2} = b^{2} + c^{2} - 2bc(cosA)$ Note: The Alternative Form of the Law of Cosines is: $cosA = \frac{b^{2} + c^{2} - a^{2}}{2bc}$ To solve the triangle, we need to find A, B, and c. We can use the Standard and Alternative Form of the Law of Cosines to solve the triangle. Finding c: $c^{2} = 9^{2} + 4.5^{2} - 2(9)(4.5)cos(105^{o})$ c = 11.06 Finding A: $cosA = \frac{4.5^{2} + 11.06^{2} - 9^{2}}{2(4.5)(11.06)}$ A = $51.79^{o}$ Finding B: $cosB = \frac{9^{2} + 11.06^{2} - 4.5^{2}}{2(9)(11.06)}$ B = $23.21^{o}$ In Total: c = 11.06 A = $51.79^{o}$ B = $23.21^{o}$