Isaiah cuts open a cardboard cube along some of its edges to form the flat shape shown on the right, which has an area of $18$ square centimeters. What was the volume of the cube in cubic centimeters?

A. $3\sqrt{3}$

B. $6$

C. $9$

D. $6\sqrt{3}$

E. $9\sqrt{3}$

1. 2025 AMC 8 官方解析

Answer (A): The flattened cube has an area of $18\text{cm}^2$ and $6$ square faces, so each face has an area of $\frac{18}{6} = 3\text{cm}^2$. Thus the side length of the cube is $\sqrt{3}\text{cm}$, and the volume of the cube is $(\sqrt{3})^3 = 3\sqrt{3}\text{cm}^3$.