What is the lens a geographer uses to investigate a geographic issue

place, space, and scale

Explanation:

A geographer investigate issues from the view point of location according to place, space and the scale.

The place is an element of location that describes the position or the domain of occurrence of issue.

Space refers the area occupied by a body or the area where an issue is domiciled.

The scale refers to the magnitude at which an issue is view or observed.

Geographers tends to synthesize and combine these different lenses to observe and investigate an issue. Almost everything on earth can be correlated spatially using these lenses.