Question

Find the length of c if a=62 degrees and angle b =39 degrees and b = 15.

Answer 1

is 62 an angle measure?

Answer 2

yea

Answer 3

ok I got you...let me set it up.

Answer 4

First thing you need is the measure of angle C. You can find that by subtracting 39 and 62 from 180. The difference is C.

Answer 5

79

Answer 6

Angle C is...79, right!

Answer 7

yea

Answer 8

Now you need to tell me that you are familiar with the Law of Sines

Answer 9

sorta im a little rusty

Answer 10

Ok, it looks like this:

Answer 11

\[\frac{ sinA }{ a }=\frac{ sinB }{ b}=\frac{ sinC }{ c }\]There are 2 things you need to know about this: the lowercase letters are side lengths while the uppercase are angles, and you only need two of those identities to solve for either a missing length or missing side.

Answer 12

You have angle B and the side length of b, you also have angle C now and you want side c. So that gets set up like this:

Answer 13

\[\frac{ sinB }{ b}=\frac{ sinC }{ c }\]and you have three of the 4 of those needed. You have this:\[\frac{ \sin(39) }{ 15 }=\frac{ \sin(79) }{ c }\]

Answer 14

To solve for side c you will cross multiply. Can you do that?

Answer 15

1185=39c

Answer 16

here...