Use the Law of Sines. Find m
|dw:1432755865708:dw|
m<c?
yes, the measure of angle C.
@Nnesha @perl @Preetha
so we need ti find sin24
but it's not a right triangle.
does that still apply?
I don't understand the Law of Sines
yes it still apply just write sin24
okay
I got 0.4067....
@sparrow2
so just enter this in the formula and then round nearest tenth
what formula?
@perl
law of sines
I don't know the formula.
162/sinc=77/sin24
then find sinc and look at the table to the relevant angle
what table? and I'm very confused right now..
values of trig function at different angle
Does it make sense up to here $$ \Large \frac{\sin 24^o}{77}= \frac{\sin C}{162} $$
why is it like that?
here is a diagram of the law of sines http://www.mathworksheetsgo.com/sheets/trigonometry/advanced/law-of-sines-and-cosines/images/picture-law-of-sines-formula.jpg
ohhhh, yes that makes sense.
so we are using just two parts of the three part ratio
you can do that since they are equal
okay.
we don't know `sin B` and `b` anyway at this point , yet
and we have to solve for C?
$$ \Large{ \frac{\sin 24^o}{77}= \frac{\sin C}{162} \\~\\ \iff \\~\\ \sin 24^o \times 162 = 77 \times \sin C \\~\\ \iff \\~\\ \frac{\sin 24^o \times 162}{77} = \sin C }$$
okay. and how do we isolate C?
$$ \Large{ \frac{\sin 24^o}{77}= \frac{\sin C}{162} \\~\\ \iff \\~\\ \sin 24^o \times 162 = 77 \times \sin C \\~\\ \iff \\~\\ \frac{\sin 24^o \times 162}{77} = \sin C \\~\\ \iff \\~\\ \sin^{-1} \left( \frac{\sin 24^o \times 162}{77} \right)= C }$$
that's what I thought, okay.
make sure you are in degree mode if you are using a TI 83/84/85 calculator
I got 58.8
is that right?
yes :)
|dw:1432757526103:dw|
Oh, wow. Thank you so much! I might need your help later, but I don't know. \(\Huge\rlap{\tt\color{teal}{Thank~you!}}{\;\tt\color{lime}{Thank~you!}}\)
Now try to 'solve' the triangle (find all side lengths and angles). You can find angle B using the fact that three angles of any triangle add up to 180. Then use law of sines one more time to find side b, or alternatively you can use law of cosines
Your welcome :)
Join our real-time social learning platform and learn together with your friends!