1. How many surfaces must the Smiths apply concrete to, so that the pool is properly sealed? Surfaces need concrete. 2. -Length- Rectangular Prisin Height If the pool has a length of 65 feet across, a width of 20 feet, and a depth of 15 feet, what is the Total Surface Area(in ft) that needs to be concreted? Width Total Surface Area je 3. It cost $5.00 a square foot for concrete. what is the total cost to seal the entire pool with concrete?