Do u have to have a cable with the teiangle peice in the middle for this to work, if so what ia it called cuz ive shopped evwrywhere and cant find it

This is a 3-wire 30 amp dryer receptacle, the cable should already be in the wall. If this is a new installation the cable should be 10-3 NM-B cable and the receptacle should be a 4-wire 30 amp dryer receptacle. If the 3-wire dryer receptacle is existing all you need for your dryer is a 3-wire 30 amp dryer cord that comes with the proper plug on it from the factory. There is nothing that fits the triangular area. Try searching for Lowes item #148708.