Surface Area and Volume help!?

Question

please help, i need to know how to find the volume and surface area of a pentagonal bipyramid.

what equation? thanks.

Answer 1

I've never heard of a bi-pyramid.  Sorry.

Answer 2

A pentagonal bipyramid is a solid that looks as if you had glued two congruent pentagonal pyramids by their bases. But the lateral faces of these pyramids are equilateral triangles.  

Let´s said that the pentagons have sides of length s. The surface area is made of 10 equilateral triangles of side s:

SA = 10 (sqrt(3)/4*s) = 5/2*sqrt(3)*s

V = 5/3 ash

where a is the apothema of the pentagonal base, which you can figure out using trigonometry;  s is the length of the sides of the pentagon, and h is the height of the pyramid.

Answer 3

ye