Answer:
[tex] {20.25 \: cm}^{2} [/tex]
Step-by-step explanation:
If the cross section is cut perpendicular to the base, it will be like an upside down T where the _ is the base and the | is the cross section.
This means the measurements of the cross section will be the width × height.
Because this shape is a cube, we know these measurements will both be 4.5cm.
4.5 × 4.5 = 20.25
The area of the cross section is 20.25 square centimeters.