<span>Your answer is </span>

<span>
</span>
I'm doing the exact same one an i got 48 cubic units for the volume. I still have to draw the rectangular figure though.
143 is composite. To be prime it has to have only 2 divisors i.e it's self and one but since it has 4 divisors ( 143, 1, 11 and 13) it is composite.
45/45/90 triangle has side ratios s/s/sroot2
leg = root 5
Other leg is also root 5
X is Hypotenuse which would be root 5 * root 2
root 5*2 = root 10