[br][img width=170,height=193]http://www.mathsisfun.com/geometry/images/cone-shiny.jpg[/img][br][br][size=200][b][u]Cone Facts:[br][/u][/b][/size][br][b]Notice these interesting things:[/b][br][list][*]It has a flat base[/*][*]It has one curved side[/*][/list][br] [br][img]http://www.mathsisfun.com/geometry/images/cone-apex-base.svg[/img][br] [br][list][*]The pointy end of a cone is called the [b]apex[/b][/*][*]The flat part is the [b]base[/b][/*][*]An object shaped like a cone is said to be [b]conical[/b][/*][/list][br][b][u][size=200]Surface Area of a Cone:[br][/size][/u][/b][br][img]http://www.mathsisfun.com/geometry/images/cone-dimensions.svg[/img][br][br]The Surface Area has two parts:[br][list][*]The [i]Base Area [/i]= π × r[sup]2[/sup][/*][*]The [i]Side Area[/i] = π × r × s[/*][/list][br]Which together makes:[br][b]Surface Area = π × r × (r + s)[/b][br]Note: we can calculate [b]s = √(r[sup]2[/sup]+h[sup]2[/sup])[br][/b][br][b][u]Example: [/u][/b]h = 7 and r = 2[br][br]Surface Area of Base= π × r[sup]2[/sup][br]      = π × 2[sup]2[/sup][br]      = 4π[br]      ≈ [b]12.57[/b][br] [br]Surface Area of Side= π × r × √(r[sup]2[/sup]+h[sup]2[/sup])[br]      = π × 2 × √(2[sup]2[/sup]+7[sup]2[/sup])[br]      = π × 2 × √(4+49)[br]      = 2π√(53)[br]      ≈ [b]45.74[br][/b][br]Total Surface Area ≈ 12.57 + 45.74 ≈ [b]58.31[br][br][/b][br][b][u][size=200]Volume of a Cone:[/size][/u][/b][br][br][b]Volume = 1/3 π × r[sup]2 [/sup]× h[/b][br][br][b][u]Example:[/u][/b] h = 7 and r = 2[br][br]Volume= 13 π × r[sup]2[/sup] [sup][/sup]× h[br]   = 13 π × 2[sup]2[/sup] [sup][/sup]× 7[br]   = 283 π[br]   ≈ [b]29.32[br][br][br][u][size=200]Volume of a Cone vs Cylinder:[br][/size][/u][/b][br][img]http://www.mathsisfun.com/geometry/images/cone-vs-cylinder.svg[/img][br][br]The volume formulas for cones and [url=http://www.mathsisfun.com/geometry/cylinder.html]cylinders[/url] are very similar:[br][br][table][tr][td]The volume of a cylinder is:  [/td][td]π × r[sup]2 [/sup]× h[/td][/tr][tr][td]The volume of a cone is:  [/td][td]1/3 π × r[sup]2 [/sup]× h[/td][/tr][/table][br][b]So a cone's volume is exactly one third ( 13 ) of a cylinder's volume.[br][/b][br][br][b][u][size=200]Different Shaped Cones:[/size][/u][/b][br][br][img width=127,height=220]http://www.mathsisfun.com/geometry/images/cone-wood1.jpg[/img][img width=173,height=220]http://www.mathsisfun.com/geometry/images/cone-wood3.jpg[/img][img width=199,height=220]http://www.mathsisfun.com/geometry/images/cone-wood4.jpg[/img][br][br][b]Construction Cone[br][/b][br][img]http://www.mathsisfun.com/geometry/images/cone-construction.svg[/img][br]This is [i][b]almost[/b][/i] a cone, but the top is chopped off (called a "truncated cone").[br]Also it has a wider base added so it doesn't fall over![br]