Final answer:
Mathematics questions concerning measurements of a rectangular garden, unit conversions, and scale drawings are typically considered middle school level problems.
Step-by-step explanation:
The question involves specific measurements related to fencing off a piece of land and falls under the subject of mathematics. This seems like geometry, which is typically taught in middle school and beyond. The problem requires an understanding of the properties of shapes as well as basic arithmetic operations to determine the length of a fence surrounding a rectangular garden and to solve similar questions related to scale drawings and unit conversion (from yards to feet to inches).
Rectangular shapes, unit conversions, and scale drawings are all mathematical concepts that are pertinent to these types of questions. For example, if Lenny wants to fence his garden, he would need to calculate the perimeter of his rectangular garden, which is calculated as 2 times the length plus 2 times the width, resulting in a total fence length of 2(12 units) + 2(4 units) = 32 units.