Surface Area of 3 D Figures Define Surface

Surface Area of 3 D Figures

Define Surface Area: • The amount of material it would take to cover a 3 D shape. • The area of everything on the outside of a space figure measured in square units

Types of space figures: a space figure with two parallel sides • Prism that are congruent • Pyramid • Cylinder a space figure with only one base; its faces are triangles a space figure with a curved surface and two congruent parallel bases that are circles (we will do this next week) • Cone a space figure with one circular base and a curved surface that comes to a point (we will do this next week) • Sphere a space figure with no bases and only curved surfaces (we will do this next week)

Surface Area of a Prism/Pyramid Sum of the area of its faces Steps: 1. Draw and label all of the faces 2. Find the area of each face 3. Add all of the faces together

Find the surface area of the following prism: 8 2 of them 8 cm 2 of them 7 6 7 cm 6 cm 5 A = (b)(h) A = ½ (b)(h) = (5)(8) = ½ (6)(7) 2 = 80 cm = 40 (2) 2 = 21(2) = 42 cm 5 6 Total Area = 42 + 80 + 30 = 152 cm 2 A = (b)(h) = (5)(6) = 30 cm 2

Find the surface area of the following Square Pyramid: 10 4 of them 12 cm 12 10 cm 10 A = ½ (b)(h) = ½ (10)(12) = 60(4) = 240 cm 2 10 A = (b)(h) = (10) = 100 cm 2 Total Area = 240 + 100 = 340 cm 2

Surface Area of a Cone Steps: 1. Identify the radius and slant height 2. Plus r and s into equation

Find the surface area of the following prism: 2. 6 m 4 m r = 4/2 = 2 s = 2. 6 m

Surface Area of a Sphere Steps: 1. Identify the radius 2. Plus r into equation

Find the surface area of the following prism: r = 9/2 = 4. 5 9 in