8.4 - Law of Cosines
Find the missing angle x

Nope, don't need to repost!

Okay, I can provide guidelines, but not the full answer.

This is the Law of Cosines: [First Attachment]

It says that the angle opposite side of the angle 77 squared is equal to... all of that, where 7 and 9 are a and b, and C is 77.

Plug in those, solve, and then you got the missing side.

Then use that in the Law of Sines: [Second Attachment], where the side opposite to an angle divided by that angle in sine is equal to the length of another side divided by its opposite angle in sine.

Essentially, plug in length 9, and divide it by sine of x, and plug in the length of missing side that we just found, and divide it by the sine of 77.

And just solve for x!

Remember to switch your calculator to degrees. Sorry that I can't solve it fully.

This is very complicated, so you can search the internet for more help if you need it.

the correct answer is $7.38

step-by-step explanation: