Part 6: please assist me with these problems

 12) 34°     13) 90°

Step-by-step explanation:

12) Given: a = 10.2,  b = 6.8, A = 122°

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

Note: The letters can be swapped

13) Given: a = 3,  b = 4,  c = 5, C = ???

3² = 4² + 5² - 2(4)(5) · cos C

9  = 16 + 25 - 40 cos C

9 = 41 - 40 cos C

-32 = -40 cos C

0.8 = cos C

90° = C

3 ft

step-by-step explanation:

since the triangle is right use pythagoras' identity to solve for a

the square on the hypotenuse is equal to the sum of the squares on the other two sides, that is

a² + 8² = ( )²

a² + 64 = 73 ( subtract 64 from both sides )

a² = 9 ( take the square root of both sides )

a = = 3

theres no picture: /

step-by-step explanation: