You can drag the monkey and bloon around and the monkey will face it and tell you the angle. Actual projects: https://scratch.mit.edu/studios/35756045/
Thanks to @SamadiBeligaswatte1 for the help. If you're curious to how this works I just took the X and Y distance between the bloon and the monkey and found the hypotenuse using the pythagorean theorem. I then took the inverse cosine of the Y difference and the hypotenuse and multiplied it by the sign of the X difference. This gets us the direction that the monkey should look to face the bloon. However, this does create one flaw where the monkey faces in direction 0 (AKA straight up) if the bloon is directly under it but this is very specific and shouldn't be much of an issue. You can look inside the project and use the code for your own projects. If you're wondering why I can't just use the direction block instead of doing all of that math, it's because in the tower defense game, there can be multiple bloons on the screen at once meaning that I can't just tell the monkey to point towards a bloon as it wouldn't know which one to face. Anyways, sorry about this confusing description I know it was a lot. If you're still reading this I really appreciate it! Have a nice day :)