What is the value of x?

Answer/Step-by-step explanation:
well, first figure out how many units/times prism A was enlarged to become prism B...
16 ÷ 2 = 8
Now if we apply that info to the length of the prism, then...
80 ÷ 8 = 10
Therefore x = 10
And the Prisms remain congruent and proportional!