There's no equations here...
Answer:
24cm
Step-by-step explanation:
a radius is half the diameter
12x2=24
R could be anything. But when you multiply it with 6 it should give you a result of a number less than 3.
Example: if r=0.1, 0.1x6=0.6 which is less than or equal to 3.
The greatest number r can be is 1/2
V = 1/2B*H*L
V = 12*35*40/2
V= 16,800/2
V= 8,400

The volume of the right prism is B) 8,400