To get the lateral surface area, all you need is this formula:
A = 6ah
Where:
a = base edge
h is the height
You have the base edge, which is 14.5 cm and the height is 26.5cm
Now all you need to do is input what you know into the formula and solve what you do not know.
A = 6ah
= (6)(14.5cm)(26.5cm)
= 2,305.5 [tex] cm^{2} [/tex]
The area of the piece of plastic is 2,305.5 [tex] cm^{2} [/tex]