A rectangular pyramid has a volume of 1,512 inches cubed, a height of 12 in., and a base length of 21 in. What is the width of its base?
2 in.
6 in.
12 in.
18 in.

Respuesta :

Answer:

Option D. 18 in

Step-by-step explanation:

Since volume of a rectangular pyramid has a volume = 1512 in³

Height of pyramid = 12 in

Rectangular base having length = 21 in

we have to find the width of the base of pyramid.

Since volume of pyramid = [tex]\frac{1}{3}(area of base)(height)[/tex]

[tex]1512=\frac{1}{3}(21.b)(12)[/tex]

1512 = 4(21b)

1512 = 84b

[tex]b=\frac{1512}{84}=18 in[/tex]

Therefore width of the rectangular base of pyramid is 18 in

Option D is the answer.

Answer:

Option D.

Step-by-step explanation:

The volume of a rectangular pyramid is

[tex]Volume=\frac{1}{3}lwh[/tex]

where, l is the length of the base, w is the width of the base and h is the height.

It is given that

[tex]1512=\frac{1}{3}(12\times 21\times w)[/tex]

[tex]1512=84h[/tex]

Divide both sides by 84.

[tex]\frac{1512}{84}=w[/tex]

[tex]18=w[/tex]

The width of its base is 18 in. Therefore, the correct option is D.