Answer:
this is a incomplete math problem and you confused me when you said 6=-2???
Step-by-step explanation:
Answer: V≈1642 cm³.
Step-by-step explanation:
D=20 cm d=12 cm h=8 cm V=?
Drawing a diagonal means to connect a vertex with another non-adjacent vertex.
So, for each vertex, we have 8-3=5 possible diagonals. This leads to a total of 8*5=40 diagonals.
We have to divide this number by 2 though, because in this way we're counting each diagonal twice (connecting points AB or BA gives the same diagonal).
So, an 8 sided shape has 20 diagonals.
4+4 = 8
But the one above is one less so you minus one from eight:
8-1 = 7
Hope this helps! :)