I answer is 54a hope this help
        
                    
             
        
        
        
The answer is 
V = 34,992 y^3You can answer this using an online calculator - calculator soup dot com under geometry then pyramid. Select given a (side length) and s (slant height). Enter the amounts to find V (volume).
To manually compute, get the h (height) first before computing for V (volume).
h^2 = l^2 - (s/2)^2  :  l (slant height), s (base edge/side)
h = √((45^2) - (54/2)^2)
h = 36
Then find V (volume) : s (side), h (height)
V = 1/3 (s^2)(h)
V = 1/3 (54^2)(36)
V = 34,992 y^3
 
        
        
        
To find volume you do length*width*height 
therefore it would be 15*8*10= 1,200
        
             
        
        
        
Hello!
The sum of all angle measures in a heptagon in 900°. We will subtract all of these angles from 900 to find our answer.
900-146-122-142-140-110-142=98
x=98°
I hope this helps!