MYP Geometry, 3-D Object Summary Surface Area is about COVERAGE; the Area of All Surfaces. Volume is about SPACE. How much it takes to fill. STEPS: 1) Identify Object, 2) Identify Formula, 3) SOLVE FOR MISSING PARTS***, 4) Plug and Chug! Object Surface Area SA = 4 𝜋𝑟 2 Sphere Volume 4 3 𝜋𝑟 3 2 𝑉 = 𝜋𝑟 3 𝑉= SA = 3 𝜋𝑟 2 Hemisphere Cylinder Prism Cone 3 SA = 2B + LA SA = 𝟐𝝅𝒓𝟐 + 𝟐𝝅𝒓𝒉 SA = 2B + Ph V = Bh V = 𝜋𝑟 2 ℎ V = Bh SA = B + LA SA = 𝝅𝒓𝟐 + 𝝅𝒓𝒍 V = 𝑩𝒉 𝟑 1 𝑉 = 𝜋𝑟 2 ℎ 3 𝟏 Pyramid SA = B + LA SA = B + ½ Pl Variables: LA = Lateral Area h = height of the OBJECT l = slant height SA = Total Surface Area r = radius B = AREA of the BASE 𝟏 V = 𝑩𝒉 𝟑 V = Volume P = Perimeter of the BASE ***Solving for missing parts may include many of the following previously learned formulas and skills*** Shape Parallelogram: Triangle: Trapezoid: Rhombus: Circle: Regular Polygon: b = base h = height Area Formula A=b●h A=½b●h A = ½ (b1+b2) ● h A = ½ (d1 ● d2) A = 𝜋 ∙ 𝑟2 A=½P●a Variables: d = diagonal r = radius P = perimeter Pythagorean Theorem c2 = a2 + b2 Soh Cah Toa sin Ɵ = o/h cos Ɵ = a/h tan Ɵ = o/a a = apothem 30-60-90 45-45-90 n – n √3 – 2n n – n - n√2