Part 5 please assist me with this problems

 14) 44°    15) 6.5

Step-by-step explanation:

Law of Cosines: a² = b² + c² - 2bc · cos A

Note: The letters can be swapped

14) Given: a = 7,  b = 6,  c = 10, A = ???

7² = 6² + 10² - 2(6)(10) · cos A

49 = 36 + 100 - 120 cos A

49 = 136 - 120 cos A

-87 =  - 120 cos A

0.725 = cos A

43.5° = A

15) Given: A = 21°,  b = 18,  c = 16

a² = 18² + 16² - 2(18)(16) · cos 21°

   = 324 + 256 - 576 cos 21°

   = 580 - 576 cos 21°

   = 42.26

   = 6.5