In an experimental, independent variable.

Aregular polygon has angkes of size 150° each.how many side has the polygon

Does heating a metal wire increase or decrease its electrical resistance? why?

The gun from the crime scene shows tool marks where the serial numbers are ground off. there are also tool marks on the bullets left behind. what information can the tool marks on the bullets and gun provide about the crime? what type of evidence does this information provide, individual or class?