Physical Quantity of the Dimensions of Length:
- To form a physical quantity of the dimensions of length using the given quantities c, G, and e^2/4π€, we need to consider their dimensions and manipulate them accordingly.

Dimensions of the Given Quantities:
- The dimension of the speed of light (c) is [LT^-1], where L represents length and T represents time.
- The dimension of the gravitational constant (G) is [L^3M^-1T^-2], where M represents mass.
- The dimension of the elementary charge squared divided by 4πε0 (e^2/4π€) is [L^3MT^-2].

Forming a Quantity of Length Dimension:
- We can combine the given quantities in a way that cancels out the unwanted dimensions, leaving us with the dimensions of length.
- One possible combination could be (c^2G(e^2/4π€))^1/5, which results in a quantity with dimensions [L].

Explanation:
- By carefully manipulating the given quantities c, G, and e^2/4π€, we can form a physical quantity with the dimensions of length. This process involves understanding the dimensions of each quantity and combining them in a way that results in the desired dimension.