Answer:
<u>The correct answer is B. ∠X = 28.6°, ∠Y = 31.2°, ∠Z = 120.2°</u>
Step-by-step explanation:
Let's recall that for solving a SSS triangle, we :
1. Use the Law of Cosines first to calculate one of the angles
2. Use The Law of Cosines again to find another angle
3. Finally use angles of a triangle add to 180° to find the last angle.
1. Cos x = (9² + 15² - 8.3²/2 * 9 * 15)
Cos x = (81 + 225 - 68.89/270)
Cos x = 0.878
x = Cos ⁻¹ (0.878)
x = 28.6° (rounding to the next tenth)
2. Cos y = (8.3² + 15² - 9²/2 * 8.3 * 15)
Cos y = (68.89 + 225 - 81/249)
Cos y = 0.855
x = Cos ⁻¹ (0.855)
x = 31.2° (rounding to the next tenth)
3. z = 180 - 31.2 - 28.6
z = 120.2°
<u>The correct answer is B. ∠X = 28.6°, ∠Y = 31.2°, ∠Z = 120.2°</u>
