Question

Need help learning how to apply the law of sines

Answer 1

first off, what is the law of sines tell us?

Answer 2

that a/sinA is equal to b/sinB equal to c/sinC

Answer 3

right, but i dont see how that would help us in this problem; we only know one angle and one distance ....

Answer 4

what would we use?

Answer 5

id use a tangent myself; but i might see a way for the law of sines to work out ... if need be

Answer 6

104tan(72)?

Answer 7

the angle on the other side of the river is 90 minus the angle on this side:

90-a

and we know the distance on this side as: l

sin(90-a) sin(a)
-------- = -----
l w

w = l sin(a)/sin(90-a)

Answer 8

tan(a) = w/l

l tan(a) = w

yeah

Answer 9

the tangent method is much simpler by far

Answer 10

thank you! you might wanna see my other questions that i'll post in a bit- they're all related to trig