What comes to mind when you see Δ? Do you see the shape literally, as a triangle? Or do you assign a symbolic meaning to it, perhaps assuming it is related to finding the slope of a line?
What does the word base conjure up for you when it's used in mathematics? Is your first instinct a numeric one in our familiar base-10 system, or perhaps in systems based on other numbers such as 4 or 12? Or do you think of base as part of a geometric figure? Did you envision the base of a polygon, which would be a line? Or of a polyhedron, which would be an area?