What is the missing angle in a system of concurrent parallel forces?

[kgbwolf]

I have a problem where i have found the angle for one line but i can't find the angle for the other. See attached picture i couldn't find how to add the picture to the post without a url for it. so far i have the x and y values for two line I am only missing the third line.
f1 = 1570 lb ^x 0 lb ^y
f2 = 532 lb ^x 1740 ^y i got 17 degrees as an angle for this line
fr=

 

[kgbwolf]

bump.....

 

[kgbwolf]

bump..........

 

[kgbwolf]

bump.......

 

[kgbwolf]

click the link for the photo

 

[kgbwolf]

bump////////////////////////////////////

 

[andrewchang]

add the components of the vectors

 

[kgbwolf]

without the angle i wouldn't be able to add Fr it would be FRCOs? FrSIn? how am i supposed to add that??

 

[andrewchang]

add the x components of the first two vectors (this is the x component of the Fr vector)

add the y components

these two are your components of the Fr vector

 

[kgbwolf]

thanks......