The Great War (WW1) killed many empires who had been around for hundreds of years. It introduced some very inhumane weapons such as gas, and was the 1st war when old tactics met new ones. Back then, a war on this scale has never been seen.
It also gave birth to many new nations
I don't know a lot about math
The answer is (d) first you solve 3/4
The given circumference is C = 12*pi
The formula for the circumference of any circle, with radius r, is
C = 2*pi*r
Plug in the given value of C and solve for r
C = 2*pi*r
12*pi = 2*pi*r ... C has been replaced with 12*pi
12 = 2*r ... divide both sides by pi (they cancel out)
6 = r ... divide both sides by 2
So r = 6 is the radius
