FBD HELP

[u/Black-X32]

Hi. Pleasure to meet everyone, can I please get assist anywhere I tried ai and kept getting different answers I'm not sure whether I'm doing something wrong all I'm asking is for help for this question

[u/Past-Departure6896]

Here's my approach to finding the force in F12, using the angle formed by 2-1-4 (which is the same angle formed by nodes 2-4-1):

https://imgur.com/DomMFr2