Question

Find the length

Answer 1

1) use law of cosines (first one)

Answer 2

12^2=15^2+c^2

Answer 3

12^2=15^2+c^2-

Answer 4

you are solving for a, and you are given b, c, and angle A

plug them into the formula and solve for a

Answer 5

a^2=12^2+15^2-2*12*15*cos*a

Answer 6

you also need to plug in angle A

Answer 7

a^2=12^2+15^2-2*12*15*cos110
a=22.18
a^2=492

Answer 8

awesome so a is about 22.18

for 2) same thing, solve for the missing side using law of cosines

Answer 9

we would be solving for c right

Answer 10

yes

Answer 11

c^2=18^2+8^2-(2*18*8)*cos43

Answer 12

sorry its taking me a min

Answer 13

might be a parentheses issue

c^2=18^2+8^2-(2*18*8)*cos(43)

otherwise try wolframalpha.com

Answer 14

you need to scroll down to get the value of c

Answer 15

so -2 and 2

Answer 16

remember we are talking about a triangle side length so the solution cannot be negative

Answer 17

so 13.32

Answer 18

yes

Answer 19

anyway I'm going out for a bit, I'll try to be online in the evening for additional questions

Answer 20

Sounds good, enjoy