Aeronautics Technological Institute

The prism's base is a square, therefore we'll consider its dimensions as a (because the base is a square) and the height equals to 3

Total area = Total area of the right parallelepiped

$2[(a⋅a)+(3a)+(3a)]$

$2(a^{ 2 }+3a+3a)$ ---> apply the distributive property

$2a^{2} + 6a + 6a$

$2a^{2} + 12a$

The question says that this same area has $80m^{2}$ , so:

$2a^{2} + 12a = 80$ ---> $2a^{2} + 12a - 80 = 0$ ---> divide by 2 ---> $a^{2} + 6a - 40 = 0$

Applying either Bhaskara or Girard you get the results -10 and 4 .

Since the result can't be negative, the answer must be $\boxed{4}$