1. **State the problem:** We need to find which square has a greater area given their side lengths. 2. **Formula for the area of a square:** $$\text{Area} = \text{side}^2$$ 3. **Calculate the area of the blue square:** $$17.9^2 = 320.41\, \text{cm}^2$$ 4. **Calculate the area of the pink square:** $$20^2 = 400\, \text{cm}^2$$ 5. **Compare the areas:** Since $$400 > 320.41$$, the pink square has a greater area. **Final answer:** The pink square with side length 20 cm has the greater area.