Two and Three Dimensional Figures

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Advanced Geometry

Inductive Reasoning

Lesson 3

Two- and Three-

Dimensional Figures

Examples

Polygon

NO HOLES

NO CURVES

SIDES

CANNOT

OVERLAP

Named by: all vertices written in consecutive order

Convex extend the sides all extensions lie outside the figure

Concave

“caves in” extend the sides any extension crosses inside the figure

# of sides and angles

7

8

9

10 n

5

6

3

4

Names of Polygons

Name of Polygon triangle quadrilateral pentagon hexagon heptagon octagon nonagon decagon n - gon

Regular Polygon

convex polygon all the sides are congruent and all angles are congruent

Examples: Name each polygon by its number of sides.

Then classify it as convex or concave and regular or irregular.

Pentagon convex regular

Perimeter and Area of a Rectangle

Perimeter – the sum of the lengths of the sides of a polygon

Area – the number of square units needed to cover a surface

ADD ALL SIDES

A

 lw

Circumference and Area of a Circle

Circumference – the distance around a circle

C

2

 r A

Area

  r 2

Example:

Mr. Smith has a circular fence that encloses an area with a diameter of 12 feet. Using the same fence, he wants to create a square fence. What is the maximum side length of the square?

Example:

Find the perimeter of a square with an area of 30 square centimeters.

Example:

Find the circumference of a circle with an area of 36

 square units.

Example:

Find the length of each side of the polygon below if its perimeter is 20 units.

Polyhedron

Definition: a solid with all flat surfaces that enclose a single region of space

•All flat surfaces are called faces.

•The line segments where the faces intersect are edges.

•The points where the edges intersect are

vertices.

Prisms

The two bases are parallel AND congruent.

Named by: the shape of the bases

Triangular Prism Rectangular Prism Pentagonal

Prism

A regular prism has bases that are regular polygons.

Pyramids

one base

Named for: the base

Triangular

Pyramid

Rectangular

Pyramid

Hexagonal

Pyramid

Examples : Identify each solid. Name the bases, faces, edges, and vertices.

This picture is on page 62 in your textbook.

Bases –

Faces –

Edges –

Vertices –

Examples : Identify each solid. Name the bases, faces, edges, and vertices.

This picture is on page 61 in your textbook.

Bases –

Faces –

Edges –

Vertices –

Cylinders Cones

The two bases are congruent, parallel circles.

one circular base

Spheres

NOT polyhedra (polyhedrons)

Examples : Identify each solid. Name the bases, faces, edges, and vertices.

This picture is on page 62 in your textbook.

Bases –

Faces –

Edges –

Vertices –

Examples : Identify each solid. Name the bases, faces, edges, and vertices.

This picture is on page 61 in your textbook.

Bases –

Faces –

Edges –

Vertices –

Height vs. Slant Height

Surface Area and Volume

P

Perimeter of thebase

B

area of the Base l

slant height

Prisms

SA

Ph

2 B

V

Bh

Pyramids

SA

1

2

Pl

B

1

V Bh

3

Surface Area and Volume

Cylinders

SA

2

 rh

2

 r 2

 

2 V r h

Cones

SA

  rl

  r 2

V

1

3

2 r h

Examples: Find the surface area and volume of the square prism.

Examples: Find the surface area and volume of the square pyramid.

This picture is on page 62 in your textbook.

Examples: Find the surface area and volume of the square pyramid.

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