To find the length of the side of the supply closet labeled with the question mark, we can calculate based on the total area of the closet.
Let's denote the width of the removed rectangular area as \( W \).
From the description, the remaining width of the closet (on the left side) is 3 feet, and the remaining length (on the right side) is 2 feet. We can set up the total area of the shape with the following formula:
\[ \text{Area} = \text{Length} \times \text{Width} \]
Given that the total area of the supply closet is 36 square feet:
\[ \text{Area} = \text{Remaining Length} \times \text{Remaining Width} = 2 \text{ feet} \times (3 + W) \text{ feet} = 36 \text{ square feet} \]
This means:
\[ 2 \times (3 + W) = 36 \]
We can now solve for \( W \):
- Divide both sides by 2:
\[ 3 + W = 18 \]
- Subtract 3 from both sides:
\[ W = 15 \]
The dimension of the side of the closet labeled with the question mark is thus 15 feet.
So the answer is:
15 feet