Question

6. In , a = 6, b = 7, and c = 8. Find the measure of angle A, correct to the nearest degree.

Answer 1

can someone please explain it to me step by step

Answer 2

law of cosines to start

Answer 3

okay! then

Answer 4

\[a^2=b^2+c^2-2bc\cos(A)\]
\[\frac{b^2+c^2-a^2}{2bc}=\cos(A)\]

Answer 5

once you have
\[\cos(A)\] as a number , take the inverse cosine to get the answer
we can do it if you like

Answer 6

i now what the law of cos are soo then all i do is pulg it in

Answer 7

in other words the answer is
\[A=\cos^{-1}(\frac{b^2+c^2-a^2}{2bc})\]

Answer 8

yup plug it in

Answer 9

kk thankxx

Answer 10

looks like about 46.57 degrees
http://www.wolframalpha.com/input/?i=arcos%28%287^2%2B8^2-6^2%29%2F%282*8*7%29%29

Answer 11

lol thankx