Answer:
(a) 6.01 (b) 57.33
Step-by-step explanation:
(a) DF² = 10² + 12² - 2 · 10 · 12 · cos(30°)
=> DF² = 244 - 240 · cos(30°)
=> DF² = 36.154
=> DF = √36.154
=> DF ≈ 6.01
(b) [tex]\frac{12.8}{sin(63)} = \frac{12.4}{sin (B)}[/tex]
=> sin (B) = sin (63) × 12.4 ÷ 12.8
=> B = sin^-1 (sin (63) × 12.4 ÷ 12.8)
=> B = 59.67355245
180 - 63 - 59.67355245 ≈ 57.33
Law of cosines & sines:
