rectangular prism has a base area of 25 in.2 and a volume of 125 in.3 . If a rectangular pyramid has a congruent base and height congruent to the prism, what is the height of the pyramid?(1 point)

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1 answer

To find the height of the rectangular pyramid, we start with the information given about the rectangular prism:

  • Base area of the prism \( A = 25 , \text{in}^2 \)
  • Volume of the prism \( V = 125 , \text{in}^3 \)

The formula for the volume of a rectangular prism is given by:

\[ V = A \times h \]

where \( A \) is the base area and \( h \) is the height of the prism. We can use this formula to find the height \( h \) of the prism:

\[ 125 = 25 \times h \]

Solving for \( h \):

\[ h = \frac{125}{25} = 5 , \text{in} \]

Now, we need to find the height of the rectangular pyramid, which has the same base area and height as the prism. The volume \( V \) of a pyramid is given by the formula:

\[ V = \frac{1}{3} A \times h \]

Since the base area and height of the pyramid are congruent to those of the prism, we will use \( A = 25 , \text{in}^2 \) and \( h = 5 , \text{in} \). However, we need to find the height of the pyramid; we can denote this height as \( h_p \). The volume of the pyramid can also be expressed as:

\[ V = \frac{1}{3} \times 25 \times h_p \]

Since the height of the pyramid is still 5 inches (the height is congruent), we substitute \( h_p = 5 \):

Calculating the volume of the pyramid using the base area:

\[ V = \frac{1}{3} \times 25 \times 5 \]

Calculating:

\[ V = \frac{1}{3} \times 125 = \frac{125}{3} , \text{in}^3 \]

Thus, the height of the rectangular pyramid is also congruent to the height of the rectangular prism, which is:

\[ \text{Height of the pyramid} = 5 , \text{in} \]

Therefore, the height of the pyramid is \( \boxed{5} \) inches.