The dihedral angle in the staggered conformation of CH_3CH_3 is

In the staggered conformation of ethane ($\text{CH}_3\text{CH}_3$), the hydrogen atoms on adjacent carbon atoms are positioned as far apart as possible to minimize torsional strain.

When viewed along the C-C bond axis (Newman projection), the C-H bonds on the front carbon bisect the H-C-H angles on the back carbon.

This arrangement results in a dihedral angle of 60^{}^{\circ} between the adjacent C-H bonds.

Answer: 60^{}^{\circ}