[b][size=150][u][size=200]Cylinder Facts:[br][/size][/u][/size][/b][br] [img width=180,height=157]https://www.mathsisfun.com/geometry/images/cylinder-shiny.jpg[/img][br][br][b]Notice these interesting things:[/b][br][list][*]It has a flat base and a flat top[/*][*]The base is the same as the top[/*][*]From base to top the shape stays the same[/*][*]It has one curved side[/*][*]The cross-section of a cylinder is a circle[/*][/list][br][img]https://www.mathsisfun.com/geometry/images/cylinder-cross-section.svg[/img][br][br] [br]An object shaped like a cylinder is said to be [b]cylindrical.[br][/b][br] [br] [img]https://www.mathsisfun.com/geometry/images/cylinder-dimensions.svg[/img][br][br][br][b][u][size=200]Surface Area of a Cylinder:[/size][br][br][/u][/b]The Surface Area has these parts:[br][list][*][i]Surface Area of Both Ends[/i] = 2 × π × r[sup]2[/sup][/*][*][i]Surface Area of Side[/i] = 2 × π × r × h[/*][/list][br]Which together make:[br][b]Surface Area = 2 × π × r × (r+h)[/b][br][br][b][u]Example:[/u][/b] h = 7 and r = 2 [br][br]Surface Area= 2 × π × r × (r+h)[br]    = 2 × π × 2 × (2+7)[br]    = 2 × π × 2 × 9[br]    = 36 π[br]    ≈ [b]113.097[br][/b][br][b][u][size=200]Volume of a Cylinder:[/size][br][br][/u][/b]To calculate the volume we multiply the area of the base by the height of the cylinder:[br][list][*]Area of the base: π × r[sup]2[/sup][/*][*]Height: h[/*][/list][br]And we get:[br][b]Volume = π × r[sup]2 [/sup]× h[br][/b][br][b][u]Example:[/u][/b] h = 7 and r = 2[br][br]Volume= π × r[sup]2[/sup] [sup][/sup]× h[br]   = π × 2[sup]2[/sup] [sup][/sup]× 7[br]   = 28 π[br]   ≈[b]  87.96[/b][br][br][b][u][size=200]Volume = pizza[/size][/u][/b][br]How to remember: [b]Volume = pizza[/b][img]https://www.mathsisfun.com/geometry/images/cylinder-pizza.svg[/img][br]Imagine you just cooked a [b]pizza[/b].[br]The radius is "z", and the thickness "a" is the same everywhere ... what is the volume?[br][b]Volume =   [/b][b]pi[/b] × [b]z[/b] × [b]z[/b] × [b]a[/b][br](we would normally write "pi" as π, and [b]z[/b] × [b]z[/b] as [b]z[sup]2[/sup][/b], but you get the idea!)