BEST ONE GETS BRAINLIST but..... if u answer something thats not really the answer im reporting u bc ik when you are useing me for points AND PLZ SHOW WORK OR TELL ME HOW YOU KNOW extra points

Answer:
16.2
Step-by-step explanation:
If you want to get the volume of the rectangular prism, than you would have to multiply the width, long and tall. So I guess it will have to be 1.2x3x4.5=16.2