Assuming that the given measures are for a rectangular block:
The largest face of the block will be the one made with the greater dimensions, which are the width and the length.
To determine the area of this rectangular face, you have to multiply both dimensions:
![\begin{gathered} A=w\cdot l \\ A=5.2\cdot6.4 \\ A=33.28\operatorname{cm}^2 \end{gathered}]()
The area of the largest face of the block is 33.28 cm²
To calculate the volume of a rectangular prism, you have to calculate the product of its width, length, and height following the formula.
![\begin{gathered} V=w\cdot l\cdot h \\ V=5.2\cdot6.4\cdot3.8 \\ V=126.464\operatorname{cm}^3 \end{gathered}]()
The volume of the block is 126.464 cm³