11.2 Surface Area 11.2 Surface Area of Prisms & of Prisms &

CylindersCylinders

PrismPrismA polyhedron with two

congruent faces (bases) that lie in parallel planes.

The lateral faces are parallelogramsThe height is the perpendicular distance between the bases

Surface Area (SA): the sum of the areas of its faces

Lateral Area (LA): the sum of the areas of the lateral faces

Surface AreaSurface area is found by

finding the area of all the sides and then adding those answers up.

How will the answer be labeled?

UnitsUnits22 because it is area!

Rectangular PrismHow many faces are on here? 6

Find the area of each of the faces.A

B

C

4

5 in

6Do any of the faces have the same area?

A = 5 x 4 = 20 x 2 =40

B = 6 x 5 = 30 x 2 = 60

C = 4 x 6 = 24 x 2 = 48

If so, which ones?

148 in2

Opposite faces are the same.

Find the SA

CubeAre all the faces the same? YES

4m

How many faces are there? 6

Find the Surface area of one of the faces.

A

4 x 4 = 16 Take that times the number of faces.X 6

96 m2 SA for a cube.

Triangular PrismHow many faces are there? 5

How many of each shape does it take to make this prism?

2 triangles and 3 rectangles = SA of a triangular prism

4

3

5

10 m

Find the surface area. Start by finding the area of the triangle.

4 x 3/2 = 6

How many triangles were there? 2

x 2= 12

Find the area of the 3 rectangles.

5 x 10 = 50 = front

4 x 10 = 40 = back

3 x 10 = 30 = bottom

SA = 132 m2What is the final SA?

Surface Area of a Right Surface Area of a Right PrismPrismThe surface area (SA) of a

right prism is:

SA = 2B + PhB = area of one baseP = perimeter of one baseh = height of the prism

2B represents the “base area”Ph represents the “lateral area”

Find lateral area & Find lateral area & surface areasurface area

Find lateral area and Find lateral area and surface areasurface area

Find lateral area & Find lateral area & surface areasurface area

Find lateral area & surface area

8 cm

3 cm

CylinderCylinder

A solid with congruent A solid with congruent circular bases that lie in circular bases that lie in parallel planes.parallel planes.

Lateral area: the area of Lateral area: the area of its curved surfaceits curved surface

Surface Area of a Right Surface Area of a Right CylinderCylinder

The surface area of a right cylinder is:

SA = 2B + Ph which can be written as:

SA = 2πr2 + 2πrh

Find lateral area & Find lateral area & surface areasurface area

Find total surface areaFind total surface area