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Surface area of prisms. Diagrams Not to scale To find the surface area of a prism, find the area of all the faces and add them together 10 cm 4 cm 3 cm SA = 2hl + 2wh + 2wl 2 (3)(10) + 2 (4)(3) + 2(4)(10) = = 164 cm 2 1

15 cm 6 cm The Curved Surface Area of a Cone Example Questions: Find the curved surface areas of the cones below. (to 1 dp) cm 3.1 cm SA =  rs+  r 2 SA= 3.14( 6)(15) (6) 2 SA = SA= cm 2 SA= 3.14(3.1)(4.8)+3.14(3.1) 2 SA = SA=48.19 Not to SCALE

7.3 cm SA = 4  r 2 SA = 4(3.14)( 7.3) 2 SA = cm 2 Example Questions: Calculate the surface area of the sphere below. 1 SA = 4  r 2

Questions: Calculate the radii of the spheres shown below. (to 1 dp) SA = 8.4 m 2 SA =4  r = 4(3.14)r = 12.56r = r = r 1 SA = 4  r 2

Surface Area of a Cylinder A cylinder is a prism with a circular cross- section. r2r2 r2r2  Removing top and bottom Open out 2  r h Surface Area = 2  r  rh

Surface Area of a Cylinder h A cylinder is a prism with a circular cross-section. 2r2r

Surface Area of a Cylinder 8cm Surface area = 2  r  rh 3cm SA = 2(3.14)(3) 2 +2(3.14)(3)(8) SA = SA = c m2