1103107012
Level:
C
Let \( ABCDEFA'B'C'D'E'F' \) be a regular hexagonal prism with the base edge length of \( 4\,\mathrm{cm} \) and the height of \( 8\,\mathrm{cm} \). Find the angle between the plane \( ADD' \) and the plane \( CDD' \) (see the picture).
\( 60^{\circ} \)
\( 45^{\circ} \)
\( 90^{\circ} \)
\( 72^{\circ} \)