1. The problem states that Sara's map length is 33 cm and Tanvi's map is a mathematically similar reduction. 2. The area of Tanvi's map is 19% less than Sara's map, so the area ratio is $1 - 0.19 = 0.81$. 3. Since the maps are similar, the ratio of their lengths squared equals the ratio of their areas. 4. Let $L$ be the length of Tanvi's map. Then: $$\frac{L^2}{33^2} = 0.81$$ 5. Solve for $L$: $$L = 33 \times \sqrt{0.81}$$ 6. Calculate $\sqrt{0.81} = 0.9$. 7. Therefore: $$L = 33 \times 0.9 = 29.7$$ The length of Tanvi's map is 29.7 cm.