Don't freak out Math is sometimes hard to be honest!!
Okay so number 1 and 2 are kinda your own opinion but maybe I can help with that.
Number 3 is either a triangular prism or pyramid
Number 4 is a rectangular prism
Number 5 is yes and yes; if you see the heights are the same because the 6 is the same
And the base is the same because of 2 by 2
Number 6 is volume