Question

Using the law of cosines, in triangle RST, if r=14yd, s=9yd, t=6yd, find m 10 years ago

Answer 1

do you know the formula for the law of cosines when finding an angle...?

Answer 2

c^2=a^2+b^2/2abcos(

Answer 3

whoops messed up

Answer 4

c=a2+b2﹣2abcosγ

Answer 5

got picture?

Answer 6

No, sorry. Thats all it gave me.:(

Answer 7

close,this is what you need

\[\cos(S) = \frac{r^2 + t^2 - s^2}{2 \times r \times s}\]

plug the values in and calculate, the answer is a decimal less than 1.

when you get the answer, you then then

\[\\S = cos^{-1}(answer)\]

Answer 8

okay. Ill plug it into my calculator. one sec.

Answer 9

oops correction it should read

\[\cos(S) = \frac{r^2 + t^2 -s^2}{2 \times r \times t}\]

Answer 10

okay i got 151/168

Answer 11

or .90

Answer 12

great so the next step is

\[S = \cos^{-1}(\frac{151}{168})\]

Answer 13

26

Answer 14

that was my solution

Answer 15

Thank you so much!