Surface Area of Prisms and Cylinders Geometry 6.2 Surface Area of Prisms and Cylinders

DRILL How many vertices does the picture have? Find the area of the shape: 3 12

Prism A prism is a polyhedron with two congruent, parallel bases. The other faces are called lateral faces. A prism is named by the shape of its base.

Parts of a Prism More Examples

Areas The lateral area is the area of all the lateral faces. The surface area is the area of all the lateral faces as well as the bases.

Formulas for Prism Areas L.A = ph S.A = L.A + 2B (where B is the area of the base)

Types of Prisms and Cylinder Right Prism/Cylinder: is when the altitude of the figure is parallel with all of the lateral faces. Oblique Prism/Cylinder: is when the altitude is not parallel to all of the lateral faces.

Cylinder Like a prism, a cylinder has two congruent parallel bases. However the bases of a cylinder are circles.

Areas of cylinders Lateral Area is found by finding the area of the resulting rectangle if the shape is unfolded. Surface area is the area of the rectangle plus the area of the two bases.

Formulas for Cylinders Area S.A = L.A +

Surface Area of a Cylinder Closed cylinder Surface Area = 2*Base area + Rectangle area 2*Area of base (circle) = 2*r2 Area of rectangle = Circle circumference * height = 2rh Surface Area of Closed Cylinder = (2r2 + 2rh) sq units Open cylinder Surface Area = Area of rectangle Surface Area of Open Cylinder = 2rh sq units

Can Label Investigation An intern at a manufacturing plant is given the job of estimating how much could be saved by only covering part of a can with a label. The can is 5.5 inches tall with diameter of 3 inches. The management suggests that 1 inch at the top and bottom be left uncovered. If the label costs 4 cents/in2, how much would be saved?

Homework Pages 312-314 #’s 1 – 8, 10, 12, 14, 18, 22, 28 Extra Credit