I agree with the answer above - boreal forests are the kind of forests that remain green all year, because evergreen trees can be found there. Opposite of this, temperate forests do not stay green all year, because they have deciduous trees, which means their leaves fall off.
The volume of the cone is calculated by the formula:
V = B*H/3
r=D/2 = 6/3 = 2
where B is surface area of basis and H is height.
B is circle which fomula for surface is:
B = r^2 * pi = 3^2*3,14 = 9*3,14 = 28.26
from condition of height we write:
H = 3*D = 3*6 = 18
now volume is:
If we express all of that in equation of volume we get:
V = 1/3* 3^2*3,14*18
From thousands to millions of years