boomerang285
Please help...
Determine the measure of side c, given:
a=3m
b=4m
B=41deg
Delete
Share
This Question is Closed
AravindG
Best Response
You've already chosen the best response.
1
tried cosine rule ?
boomerang285
Best Response
You've already chosen the best response.
0
im not sure how to do this at all....
AravindG
Best Response
You've already chosen the best response.
1
do u knw cosine rule ?
boomerang285
Best Response
You've already chosen the best response.
0
i have just started learning about it
AravindG
Best Response
You've already chosen the best response.
1
ok
\[\cos B=\dfrac{a^2+c^2-b^2}{2ac} \]
AravindG
Best Response
You've already chosen the best response.
1
now solve for b
t_soulb
Best Response
You've already chosen the best response.
0
yea good cosine rule,,my answer is b=2.44 (approx.)
dan815
Best Response
You've already chosen the best response.
0
u could use sin law too i think
t_soulb
Best Response
You've already chosen the best response.
0
sorry 1.22
AravindG
Best Response
You've already chosen the best response.
1
@dan815 sin law wont work cause we need two angles :/
dan815
Best Response
You've already chosen the best response.
0
sin <b/b=sin<a=a sin<(180-(a+b))/c and solve for C
dan815
Best Response
You've already chosen the best response.
0
use my equation < means angle
boomerang285
Best Response
You've already chosen the best response.
0
actually my options are:
1.6m
4.5m
0.1m
5.7m
I thought it was 1.6m?
boomerang285
Best Response
You've already chosen the best response.
0
am I wrong?
boomerang285
Best Response
You've already chosen the best response.
0
actually it was 5.7 after I figured it out.. Thanks though
dan815
Best Response
You've already chosen the best response.
0
did u use my formula!
t_soulb
Best Response
You've already chosen the best response.
0
yea approx.
boomerang285
Best Response
You've already chosen the best response.
0
yes thank you
dan815
Best Response
You've already chosen the best response.
0
np :)
dan815
Best Response
You've already chosen the best response.
0
if u remember that you need atleast 3 pieces of information to solve a triangle
and that if the angle given is the angle of the opposite side then you can always use sin law
if they give u like side a and b but give you angle C then you have to use cos law if its not a right angle triangle