MacBook Pro freezes and shuts down

[AggressiveDonut]

Hi, I'm using a 2013 MacBook Pro, Yosemite, and my laptop started freezing on me and shutting down randomly, it seems to happen especially when I do multiple tasks at the same time, e.g. Typing and changing volume at the same time.

Not only that, but my finder is now not working because of these random shut downs, there are no desktop icons, the menu bar is giving me the umbrella of death and relaunching finder does not work. Another thing is that when I try to access some parts of the system preferences, it says it cannot be loaded

EDIT: now my computer is completely dead, it's giving the beeping noise (3 times)

I think it all started when I started using iMovie, I've been using Yosemite for the past couple of months now and nothing has happened until I started using iMovie, could it be because iMovie used up so much ram that my hard drive got overheated or something? Anyway my laptop is now dead and I can't lose all my data in there, I need a way of backing it up, please help me out, thanks guys

 

[chscag]

Are you able to boot to your recovery partition? (hold down command + r and restart) If you can get into recovery, select utilities, and then Disk Utility. Verify the hard drive (SSD) for errors. The beeping can be caused by defective memory or a bad hard drive (SSD). Check the hard drive (SSD) first. We can check the memory later by downloading the "Rember" memory checking program.

Also, it would help us to know which 2013 MacBook Pro you have. I'm assuming it's a retina model?