Jessica needs another 52.8 cm^3 of material to make the other prism.
For a right triangular prism of base B, height H, and length L, the volume is:
V = (1/2)*B*L*H
Now, we know that the first triangle has a volume of 12.6cm^3, then we can write:
V = 12.6cm^3 = (1/2)*B*L*H
If we dilate the prism with a scale factor of 3, the new dimensions are:
B' = 3B
L' = 3L
H' = 3H
Then the new volume is:
V' = (1/2)*(3B)*(3L)*(3H) = 27*(1/2)*B*L*H
And (1/2)*B*L*H is the original volume, so we can write:
V' = 27*V = 27*(12.6cm^3) = 340.2 cm^3
And she has 300cm^3 and she used 12.6cm^3, so the amount of material that she has left is:
M = 300 cm^3 - 12.6 cm^3 = 287.4 cm^3
Then the amount of material that she needs is:
340.2 cm^3 - 287.4 cm^3 = 52.8 cm^3
So Jessica needs another 52.8 cm^3 of material to make the other prism.
If you want to learn more about volumes, you can read:
https://brainly.com/question/1972490