Asolid has a circular base of radius 3. if every plane cross-section perpendicular to the x-axis is an equilateral triangle, then its volume is:
a) 36
b) 12sqrt3
c) 18sqrt3
d) 36sqrt3

try to explain as much as you can, i am very confused.

How does federalist, no.10 address the concerns of a strong national government in brutus i? a) the court system would be a representative democracy and the other branches republics. b) representative gov't was the only way to check state power in the national gov't. c) states would be allowed to choose which sort of representation they have at the national level d) the national gov't would be a balance between democracy and republic, thus protecting the rights of citizens.