Question

Please help...
Determine the measure of side c, given:
a=3m
b=4m
B=41deg

Answer 1

tried cosine rule ?

Answer 2

im not sure how to do this at all....

Answer 3

do u knw cosine rule ?

Answer 4

i have just started learning about it

Answer 5

ok

\[\cos B=\dfrac{a^2+c^2-b^2}{2ac} \]

Answer 6

now solve for b

Answer 7

yea good cosine rule,,my answer is b=2.44 (approx.)

Answer 8

u could use sin law too i think

Answer 9

sorry 1.22

Answer 10

@dan815 sin law wont work cause we need two angles :/

Answer 11

sin <b/b=sin<a=a sin<(180-(a+b))/c and solve for C

Answer 12

use my equation < means angle

Answer 13

actually my options are:
1.6m
4.5m
0.1m
5.7m
I thought it was 1.6m?

Answer 14

am I wrong?

Answer 15

actually it was 5.7 after I figured it out.. Thanks though

Answer 16

did u use my formula!

Answer 17

yea approx.

Answer 18

yes thank you

Answer 19

np :)

Answer 20

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