1. **State the problem:** We have a small square with side length 20 mm. 13 copies of this square are arranged to form a larger rectangle. We need to find the area of the larger rectangle. 2. **Understand the arrangement:** The larger rectangle is made of 3 rows: the first two rows have 5 squares each, and the third row has 3 squares. So the total number of squares is $5 + 5 + 3 = 13$. 3. **Find dimensions of the larger rectangle:** - Each small square has side length 20 mm. - The width of the larger rectangle is the length of the longest row, which is 5 squares wide. - The height of the larger rectangle is 3 squares tall (3 rows). 4. **Calculate width and height:** - Width $= 5 \times 20 = 100$ mm - Height $= 3 \times 20 = 60$ mm 5. **Calculate area of the larger rectangle:** $$\text{Area} = \text{width} \times \text{height} = 100 \times 60 = 6000 \text{ mm}^2$$ **Final answer:** The area of the larger rectangle is $6000$ square millimeters.