Answer:
90 degrees
angles are measured in degrees
The volume is 30.
You need to subtract the volume of the smaller box from that of the bigger box. It is written as such:
V = (3*3*4) -(2*1*3)
V = 36 -6
V = 30
When dividing two fractions, invert the second one and multiply the 2 top numbers and the 2 bottom numbers.
3/4 / 1/4 = 3/4 * 4/1 = 12/4 = 3