Landing an airplane feels hazardous...

[Yellow Snow]

Any landing inside the white arc is a controlled crash in a 172. You should hear the stall horn wailing on every normal landing. The only time you need extra speed is for unusual winds. If you are still doing 80 when you are close to the runway you will just float right off the end if you have the correct nose up attitude. If you are trying to land at 80 you will have to force the aircraft down probably on the nosewheel and that is very dangerous. If your instructor has you trying to land at 80 perhaps you need to find a more experienced instructor.