Answer:
the answer is b. i think so.
Hi there! The answer is C.
The area of the square in the middle is the following:

Hence, the area of the square is 25 cm^2.
The area of one triangle is the following:

Hence, the total area of the four triangles is 4 × 20 = 80 cm^2.
Therefore, the total area of the pyramid is 80 + 25 = 105 cm^2. The answer is C.
That is actually easier thatn it looks
here is a tip
write that thing apart since they are all multiplication like this:
V=(1/3)pir^2 h
now just divide the whole equaiton by ((1/3)pir^2)
or if you don't like dividiing by fracitons, times both sides by 3/1 to clear fraction to get
3V=pir^2h
divide both sides by pir^2
(3v)/(pir^2)=h