A frustum of a right pyramid has a bottom base ABCD with AB = 15 cm and BC = 10 cm. The top base EFGH has FG = 6 cm. If FG is parallel to BC and EH is parallel to AB, what is the length of EH?

Step 1: Calculate the length of EH.
The figure is a frustum of a right pyramid, which means the top and bottom bases are similar rectangles.
The bottom base ABCD has sides $AB = 15 \text{ cm}$ and $BC = 10 \text{ cm}$.
The top base EFGH has side $FG = 6 \text{ cm}$.
From the diagram, $FG$ is parallel to $BC$, and $EH$ is parallel to $AB$.
Therefore, $FG$ corresponds to $BC$, and $EH$ corresponds to $AB$.
The ratio of similarity $k$ is given by the ratio of corresponding sides:

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