Answer:
112 cm²
Step-by-step explanation:
To find the surface area of the given cuboid, we can use the formula for the surface area of a cuboid:
[tex]\boxed{\begin{array}{l}\underline{\textsf{Surface area of a cuboid}}\\\\S.A.=2(wl+hl+hw)\\\\\textsf{where:}\\\phantom{ww}\bullet\;\textsf{$w$ is the width of the base.}\\ \phantom{ww}\bullet\;\textsf{$l$ is the length of the base.}\\ \phantom{ww}\bullet\;\textsf{$h$ is the height of the cuboid.}\end{array}}[/tex]
In this case, since the area of one side is given as 20 cm² and the height is 2 cm, then the length of the base of the cuboid is 10 cm.
Therefore:
- w = 3 cm
- l = 10 cm
- h = 2 cm
Substitute the values of w, l and h into the formula and solve for SA:
[tex]S.A.=2(3\times 10+2 \times 10+2 \times 3)\\\\S.A.=2(30+20+6)\\\\S.A.=2(56)\\\\S.A.=112\; \rm cm^2[/tex]
Therefore, the surface area of the cuboid is:
[tex]\Large\boxed{\boxed{112\; \rm cm^2}}[/tex]
