Question

In the figure below ABCDEFGH is a frustum of a right pyramid. The altitude of the frustum is 2cm

Calculate:

1. The altitude of the pyramid   
2. The volume of the frustum  
3. The angle between the bases of the frustum and the face ABGF  
4. The angle between base of the frustum and Face ABHE

Answer 1

1. Altitude of pyramid
   
   h+2 = 8
      h     4
   h+2  =2
     h
   h+2=2h
    h=2
   height=4cm
2. Volume of frustum
   ¹/₃×8×5×4 −¹/₃×4×2.5×2
       =53.33 − 6.667
       =46.67cm³
3.  
   
    tan θ =²/_1.25
          θ =57.99°
4.  tan θ =²/_3.75
           θ =28.07º