Final answer:
Without the minimum perimeter value, it is not possible to provide a definitive answer for the maximum cross-section of a non-circular handgrip with a maximum perimeter of 6-1/4 inches.
Step-by-step explanation:
The question refers to the dimensions of a handgrip and is asking for details regarding its cross-sectional size. To address this, we need to understand the relationship between the perimeter and the cross-sectional area of the handgrip. Though the question does not provide all the necessary numerical information to give a definitive answer, we can refer to the rule of thumb mentioned. According to this rule, handgrips used to be considered comfortable at 5 inches side-to-side and 7-8 inches deep, while newer suggestions indicate up to 8 diameters side-to-side and 15 diameters deep.
For a non-circular handgrip with a minimum perimeter not provided in the question, and the maximum perimeter of 6-1/4 inches, the maximum cross-section would be defined by these perimeter values. However, without the minimum perimeter value, we cannot give a definitive size for the maximum cross-section. It would typically be a fraction of the perimeter, considering the handgrip must enclose a space for the hand.