6.
Which expression represents the volume of the composite figure
formed by a hemisphere with radius r and a cube with side length 2r?

6 Which expression represents the volume of the composite figure formed by a hemisphere with radius r and a cube with side length 2r class=

Respuesta :

Answer:

A. [tex]r^{3}[/tex]([tex]\frac{2}{3}[/tex][tex]\pi[/tex] + 8)

Step-by-step explanation:

A composite figure is formed by two or more shapes in contact.

Volume of a cube = [tex]l^{3}[/tex]

where l is the length of its sides.

Given that l = 2r, then;

volume of the cube = [tex](2r)^{3}[/tex]

                                 = 8[tex]r^{3}[/tex]

volume of the cube = 8[tex]r^{3}[/tex]

For a hemisphere, volume = [tex]\frac{2}{3}[/tex][tex]\pi[/tex][tex]r^{3}[/tex]

Also,

volume of the hemisphere = [tex]\frac{2}{3}[/tex][tex]\pi[/tex][tex]r^{3}[/tex]

So that,

volume of the composite figure = volume of the cube + volume of the hemisphere

                                                 = 8[tex]r^{3}[/tex] + [tex]\frac{2}{3}[/tex][tex]\pi[/tex][tex]r^{3}[/tex]

                                                 = [tex]r^{3}[/tex](8 +  [tex]\frac{2}{3}[/tex][tex]\pi[/tex])

volume of the composite figure =  [tex]r^{3}[/tex]([tex]\frac{2}{3}[/tex][tex]\pi[/tex] + 8)