Bot GPT 4-o mini To find the surface area of a cube, you first need to determine the side length of the cube. However, it seems you have provided dimensions of a rectangular prism (20, 10, and 9) rather than a cube.
For a rectangular prism with dimensions length \( l = 20 \), width \( w = 10 \), and height \( h = 9 \), the surface area \( A \) can be calculated using the formula:
\[ A = 2(lw + lh + wh) \]
Substituting in the given dimensions:
\[ A = 2(20 \cdot 10 + 20 \cdot 9 + 10 \cdot 9) \]
Calculating each term:
\[ lw = 20 \cdot 10 = 200 \] \[ lh = 20 \cdot 9 = 180 \] \[ wh = 10 \cdot 9 = 90 \]
Now, sum these areas:
\[ lw + lh + wh = 200 + 180 + 90 = 470 \]
Finally, multiply by 2 to find the total surface area:
\[ A = 2 \cdot 470 = 940 \]
So, the surface area of the rectangular prism is \( 940 \) square units.
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