The Equipment Rules allow clubs to be played no more than 48 inches (121.9 cm) long. This restriction does not apply to putters.
From the January 2022, the USGA and the R&A introduced a new Model Local Rule G-10. This rule allows (but NOT OBLIGES) the Committee to limit the maximum length of a club in elite amateur golf competitions to 46 inches (116.8 cm). As before, this does not apply to putters.
When checking the length of a club, remember about the definition and formal measurement requirements. See more details on Length of the Club subpage.
To determine an angle of 60°, it is best to lean the club against a vertical wall and confirm the lie with one of the many available phone applications, e.g. Clinometer.
Alternatively, you can use the fact that cos60° = 1/2 (see Angle Units and Trigonometric Functions) and lean the club against the wall so that the distance between the head and the wall is half the length of the club.
