In this unit, you calculated the surface area of solid figures composed of polygons, such as rectangles and triangles. But imagine finding the surface area of a cylinder-a solid figure that has several curved surfaces. A cylinder is made up of two circular bases and a curved (lateral) surface in between. Develop a formula for finding the surface area of the outside of a cylinder based on what you know about the circumference of a circle and the areas of circles and rectangles. (Hint: Think about rolling a rectangular piece of paper into the shape of a cylinder.) Discuss your approach and why it works.​