1. The problem is to convert 1 acre (ac) into square feet (ft²). 2. The formula to convert acres to square feet is: $$1 \text{ acre} = 43560 \text{ square feet}$$. 3. This is a standard conversion factor used in land measurement. 4. Applying the formula: $$1 \text{ ac} = 43560 \text{ ft}^2$$. 5. Therefore, 1 acre equals 43560 square feet.