I have the Pc connected to the raspberry pi with an Ethernet cable. The raspberry pi is connected to the tv with an hdmi cable. I'm trying to use this method to use my tv as a monitor since my vga cable is broken.
you gave not much more info, but it seems to be a very "naive" question.
If you simply want all video that would appear on the PC's screen to be displayed on the screen of the PC, then there is various "remote use" software available. (realVNC is one of them, that is popular for the PI). This relies on some software running on the PC, so we need to know which OS is running on the PC.
Note that if you really mean TV, as in old fashioned composite device, then the resolution of what you get to see will be very poor, or you will only see a small part of the computers screen.