Answer:
1. a =22.184 (rounded 3 decimal places)
2. missing length = 13.318 (rounded 3 decimal places)
Explanation:
1. use law of cosine
a= sqrt( 12^2 + 15^2 - 2(12)(15)(cos110) )
a =22.184 (rounded 3 decimal places)
2. use law of cosine
missing length = sqrt( 8^2 + 18^2 - 2(8)(18)(cos43) )
missing length = 13.318 (rounded 3 decimal places)