3.5a: Surface Area of Prisms and Cylinders

GSE’s Primary

M(G&M) –10–6

Solves problems involving perimeter, circumference, or area

of two dimensional figures (including composite figures) or

surface area or volume

of three

Secondary

M(G&M) –10–2

Makes and defends conjectures, constructs geometric arguments, uses geometric properties, or uses theorems to solve problems

involving angles, lines, polygons, circles, or right triangle ratios (sine, cosine, tangent) within mathematics or across disciplines or contexts (e.g.,

Pythagorean Theorem, Triangle Inequality Theorem

)

3-D figures- Solid figures. When the sides are polygons, its called a

polyhedron

.

Prism

: a 3-D solid with 1) 2 bases – which are

parallel

and

congruent

2) lateral faces that are parallelograms * names by the shape of their bases Base Lateral Edge Altitude (height)- Distance between the bases Lateral Face – parallel sides not the base Base (parallel & Congruent)

Areas of the Solids

Lateral Area

(LA) – the sum of the areas of the lateral faces only.

– Does not include the area of the bases.

Surface Area

(SA) – the sum of the areas of ALL the faces.

– Lateral area + area of the bases

Ex: Find the lateral & surface areas of the triangular prism.

60 o  15 .

59 http://guilford.rps205.com/departments/Math/Links/Honors%20Geometry/Honors%20Geometry%20Power%20Points/12.2%20SA%20of%20Prisms%20&%20Cylinders.ppt#7

Find the Surface Area

Cylinders

: 1) has 2 circular bases 2) bases are both parallel and congruent Right cylinder – the axis is the same as the altitude Oblique Cylinder The axis is longer than the altitude altitude axis

Find the surface area and lateral area

Example

A right cylinder has a surface area of 400 square mm.

Find the height of the cylinder if the diameter of the base of the cylinder is 10 mm.

example2

If the side of a cube is doubled, what happens to the surface area ?

Challenge

The Lateral Area of a right rectangular prism is 784 square cm.

Its length is three times its width.

Its height is twice its width.

Find the surface area.

Ex. 1 – Released Item from 2007 NECAP A square with a side length of 8.0 cm is rolled up, without overlap, to form the lateral surface of a cylinder. What is the radius of the cylinder to the nearest tenth of a centimeter?

Ex 2. Find the Surface Area 13 in 12 in 5 in 4 in

Describe the solid that is made from each of these nets.

Prism

Describe the solid that is made from each of these nets.

Cube

Describe the solid that is made from each of these nets.

Pyramid

Complete the following net of a cube

Now complete the net in a different way

Complete the cuboid (rectangular prism) net

Which one of these nets can be folded to make a cube?

Yes (but with overlap) No

Which one of these nets can be folded to make a cube?

No Yes

Complete the Net of this Building

Scale:

1 square represents 1 m Plan

Homework