a)
Check the picture below.
b)
volume wise, we know the smaller pyramid is 1/8 th of the whole pyramid, so the volume of the whole pyramid must be 8/8 th.
Now, if we take off 1/8 th of the volume of whole pyramid, what the whole pyramid is left with is 7/8 th of its total volume, and that 7/8 th is the truncated part, because the 1/8 we chopped off from it, is the volume of the tiny pyramid atop.
Now, what's the ratio of the tiny pyramid to the truncated bottom?

 
        
             
        
        
        
Answer:
Step-by-step explanation:
The point of this question is to find out the point where two lines intersect. First we need to get the equation of those lines
Slope of line 1:
(Yb -Ya)/(Xb - Xa) =
(-10 - (-14))/(-1 - (-3)) =
4/2 =
2
Use that slope to find the Y-intercept of line 1
y = 2x + b
-14 = 2(-3) +b
-14 = -6 + b
-8 = b
Therefore Line 1 is:
y = 2x - 8
Slope of line 2
(11 - 13)/(-1 - (-3)) =
-2/2 =
-1
Y-intercept of line 2
y = -x + b
13 = -(-3) +b
13 = 3 + b
10 = b
Therefore line 2 is 
y = -x + 10
Now we have 2 equations to solve for the coordinates x and y
y = 2x - 8
y = -x + 10
Substitute y out in one of the equations
2x - 8 = -x + 10
3x = 18
x = 6
Plug x into one of the equations
y = 2(6) - 8
y = 12 - 8
y = 4
Therefore the solution is:
x=6, y=4
 
        
                    
             
        
        
        
Proportion can be used to find the height = 0.75
Step-by-step explanation:
A billboard is 27 feet high and casts a 36-foot shadow at noon. 
Height of billboard = 27 feet
Height of shadow of billboard = 36 feet

A fir tree next to the billboard casts a 48-foot shadow.
Height of shadow of fir tree  = 48 foot

Proportion can be used to find the height = 0.75
 
        
             
        
        
        
To find the answer we simply work out the equation.
cos (75) = 10/x 
cos (75) * x = 10. Here, I simply multiplied both sides by x to move x to the left hand side of the equation.
x = 10 / cos (75) Here, I divided cos (75) on both sides to move cos (75) to the right hand side of the equation.
The cosine of 75 is 0.92175127, so, 10 / 0.92175127 = 10.8489137
        
             
        
        
        
Answer:
Step-by-step explanation:
The answer is D. Both are negative because they're both elevations below 0. However, -7 is higher, or closer to the regular level, because -10 is simply farther down.