Warm UpFind the surface area of the following figures. Show work and include units!

1. 2.

3. 4.

3.84 mm

12.25 in4.19 in

9 ft

6.57 ft5.28 ft

19 ft

Lesson 5-2:Surface Area of

Triangular Prisms and Cylinders

I can…• find the surface area of a triangular prism.• find the surface area of a cylinder.

Vocabulary•Cylinder

Surface Area (REVIEW)

The total area of the surface of a three dimensional object

*We will use nets to help us determine the surface area

Net (REVIEW)

A two-dimensional figure that can be folded on its segments or curved on its boundaries to form a three-dimensional figure.

Right Prism (REVIEW)A prism that

has two bases, one directly above the other, and has its lateral faces as rectangles.

Triangular Prism

A prism whose bases are triangles.

Video Over Surface Area of a Triangular Prism» http://

www.youtube.com/watch?v=yHtdtsOWnDI

Surface Area of a Triangular Prism

» First, let’s draw a net of a triangular prism.

7 cm

Triangle 1 = (½*b*h) Triangle 2 = (½*b*h) = (½*8*10)

= (½*80) = 40 sq. cm

= (½*8*10)

= (½*80) = 40 sq. cm

Surface Area of a Triangular Prism

7 cm

Rectangle 1= (l * w) Rectangle 3 = ( l * w)

=(7 * 60)

= 420 sq. cm

= ( 8 * 60)

= 480 sq. cm

Rectangle 2= (l * w)

=(7 * 60)

= 420 sq. cm

Surface Area of a Triangular Prism

7 cm

Total Surface Area = Area of Triangles + Area of Rectangles

= 40 + 40 + 420 + 420 + 480= 1400 sq. cm

Examples

» What is the surface area of the triangular prism?

Triangle 1 SA= 12 sq. metersTriangle 2 SA= 12 sq. meters Rectangle 1 SA= 63 sq. meters Rectangle 2 SA= 56 sq. meters

9 m

Rectangle 3 SA= 21 sq. metersTotal = 164 sq. meters

Cylinder» A three dimensional shape with two

identical flat ends that are circular or elliptical connected by a curved surface.

Surface Area of a Cylinder

The net of a cylinder:

Video Over Surface Area of a Cylinder

» http://www.youtube.com/watch?v=GpHhvuRbB-8

Surface Area of A Cylinder Ex

Example