Geometry Surface Area of Cylinders By Mr. Wall

Surface Area  Cylinder – (circular prism) a prism with two parallel, equal circles on opposite sides. To find the surface area of a cylinder we can add up the areas of the separate faces.

Surface Area  In a cylinder there are a pair of opposite and equal circles. We can find the surface area of a cylinder by adding the areas of the two blue ends (A) and the yellow sides (B). B A

Surface Area  We can find the area of the two ends (A) by using the formula for the area of a circle.  A = π r 2 SideArea Number of Sides Total Area A B Total B A 5cm 8cm

Surface Area  We can find the area of the two ends (A) by using the formula for the area of a circle.  A = π r 2 SideArea Number of Sides Total Area A 78.5 cm cm 2 B Total B A 5cm 8cm

Surface Area  If we “unwrapped” the cylinder, what shape would the outside “B” be? SideArea Number of Sides Total Area A 78.5 cm cm 2 B Total B A 5cm 8cm

Surface Area  “B” would be in the shape of a rectangle, with the height forming one side and the circumference of the top forming the second side. SideArea Number of Sides Total Area A 78.5 cm cm 2 B Total B A 5cm 8cm

Surface Area  A = b * h  A = 2πr * h SideArea Number of Sides Total Area A 78.5 cm cm 2 B Total B A 5cm 8cm

Surface Area  A = 2πr * h  A = 2 (3.14) (5) * 8 SideArea Number of Sides Total Area A 78.5 cm cm 2 B Total B A 5cm 8cm

Surface Area  A = 2πr * h  A = cm 2 SideArea Number of Sides Total Area A 78.5 cm cm 2 B cm 2 1 Total B A 5cm 8cm

Surface Area  A = 2πr * h  A = cm 2 SideArea Number of Sides Total Area A 78.5 cm cm 2 B cm 2 1 Total cm 2 B A 5cm 8cm

Surface Area  Sketch cylinder and copy table. Work together to find the S.A. SideArea Number Sides Total Area

Surface Area  Assignment SideArea Number Sides Total Area A A 4.1m 1.9m  Sketch cylinder and copy table. Calculate S.A.