Question

For each triangle shown below, determine whether you would use the Law of Sines or Law of Cosines to find angle x. Then find angle x to the nearest tenth.

Answer 1

I dont understand how to decide which to use. I know if they say to use a specific law, how to calculate.Confused here.

Answer 2

should say "still confused here"

Answer 3

http://www.cut-the-knot.org/pythagoras/cosine2.shtml

Answer 4

10.7 by The Law of Sines (SAS)

Answer 5

??????

Answer 6

If you have two angles and a side (AngleAngleSide), or two sides and an angle(SideAngleSide) you can use Law of Sines.
Reason being is as follows:

Answer 7

Law of Sines states that \[ \frac{ a }{ sinA }=\frac{ b }{ sinB }=\frac{ c }{ sinC }\]

Answer 8

Thus if we label a triangle like so:

Answer 9

we can see that if we have Angle, Angle Side (AAS) then: