Geologic Geometry: I'm trying to figure out what the radius for the arc on the side of the car park is. It's rising uniformly from 65m to 70m so this represents a rise of 5m in total, which would make one assume that you would use a radius of 5m. Since it's fill though perhaps it is 7.5m or maybe something completely different? The textbook isn't much help on this specific area of geologic geometry.