$A_b = 6 \times \frac{1}{2}a^2 \sin 60^\circ$
$A_b = \frac{3\sqrt{3}}{2} a^2 ~ \text{unit}^2$
Crystal prism (h1 = 2a units)
$V_1 = A_b h_1 = \frac{3\sqrt{3}}{2} a^2(2a)$
$V_1 = 3\sqrt{3} \, a^3 ~ \text{unit}^3$
Crystal pyramid (h2 = a units)
$V_2 = 2 \times \frac{1}{3}A_b h_2 = 2 \times \frac{1}{3}(\frac{3\sqrt{3}}{2} a^2)(a)$
$V_2 = \sqrt{3} \, a^3 ~ \text{unit}^3$
$\dfrac{V_1}{V_2} = \dfrac{3\sqrt{3} \, a^3}{\sqrt{3} \, a^3}$
$V_1 = 3V_2$
Thus, the volume of crystal prism is three times the volume of the crystal pyramid. answer