"The surface area of a rectangular prism is 208cm (to the power of 2). two of the dimensions are 2cm and 10cm. find the measure of the others dimension."

1 answer

To find the missing dimension of the rectangular prism, we can use the formula for the surface area of a rectangular prism, which is given by:

\[ \text{Surface Area} = 2(lw + lh + wh) \]

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

Given:

  • Surface Area = 208 cm²
  • Two dimensions are \( l = 2 \) cm and \( w = 10 \) cm.

Let \( h \) be the height we need to find.

Now, we can substitute these values into the surface area formula:

\[ 208 = 2(2 \cdot 10 + 2 \cdot h + 10 \cdot h) \]

First, calculate \( 2 \cdot 10 \):

\[ 208 = 2(20 + 2h + 10h) \] \[ 208 = 2(20 + 12h) \]

Next, divide both sides by 2:

\[ 104 = 20 + 12h \]

Now, subtract 20 from both sides:

\[ 84 = 12h \]

Finally, divide by 12 to solve for \( h \):

\[ h = \frac{84}{12} = 7 \]

Thus, the missing dimension \( h \) is:

\[ \text{Height} = 7 \text{ cm} \]