Answer:
2004 cm²
Explanation:
To solve this problem, you just need to plug your values into the rectangular prism formula: A=2(wl+hl+hw)
Assuming that the length is 21 cm, the width is 18 cm, and the height is 16 cm, your problem would look like this:
A=2((18x21)+(16x21)+(16x18))=2(378+336+288)=2x1002=2004 cm²