Melissa has a gerbil that lives in a cage in the shape of a rectangular prism. She

wants to put a ramp in the cage to give her gerbil exercise. The cage has a length
of 70 cm, a width of 35 cm, and a height of 50 cm. How long does the ramp need to
be to fit diagonally in the cage? Round the answer to the nearest tenth. (1 point)
92.9 cm
60.2 cm
78.6 cm
116.3 cm

1 answer

To find the length of the ramp needed to fit diagonally in the cage, we can use the 3-dimensional version of the Pythagorean theorem. The formula to find the diagonal \( D \) of a rectangular prism is:

\[ D = \sqrt{l^2 + w^2 + h^2} \]

where \( l \) is the length, \( w \) is the width, and \( h \) is the height of the prism.

In this case, Melissa's cage has the following dimensions:

  • Length \( l = 70 \) cm
  • Width \( w = 35 \) cm
  • Height \( h = 50 \) cm

Now, we will calculate the diagonal:

\[ D = \sqrt{(70)^2 + (35)^2 + (50)^2} \]

Calculating each of the squares:

\[ (70)^2 = 4900 \] \[ (35)^2 = 1225 \] \[ (50)^2 = 2500 \]

Now, summing these values:

\[ D = \sqrt{4900 + 1225 + 2500} = \sqrt{8625} \]

Now, we calculate \( \sqrt{8625} \):

\[ D \approx 92.9 \text{ cm} \]

Rounding to the nearest tenth, the length of the ramp needed to fit diagonally in the cage is approximately 92.9 cm. Therefore, the correct answer is:

92.9 cm