# Perimeters and areas of composite figures - PowerPoint PPT Presentation

PPT – Perimeters and areas of composite figures PowerPoint presentation | free to download - id: 1d1352-ZTM1N

The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
Title:

## Perimeters and areas of composite figures

Description:

### A composite figure is a plane figure made up of simple ... area of a region is equal to the sum of the areas of its nonoverlapping parts. A = A1 A2 A3 ... – PowerPoint PPT presentation

Number of Views:2578
Avg rating:3.0/5.0
Slides: 10
Provided by: stud1096
Category:
Transcript and Presenter's Notes

Title: Perimeters and areas of composite figures

1
Perimeters and areas of composite figures
• A composite figure is a plane figure made up of
simple shapes or a 3-dimensional figure made up
of simple 3-dimensional figures.

2
Perimeter
• The perimeter of a plane composite figure is the
sum of the lengths of its sides

20 in.
12 in.
3
Be careful !!!
• Can the perimeter of a composite figure be found
by adding the perimeters of the shapes that
compose it?
• NO! NO! NO! because this would be counting the
"internal sides" and they should not be counted
at all.

4
Area congruence postulatePostulate 19
• If 2 polygons are congruent, then they have the
same area

5
• The area of a region is equal to the sum of the
areas of its nonoverlapping parts
• A A1 A2 A3

A3
A2
A1
6
HINT
• Sometimes a figure will need to be divided into
parts in order to find the area. Look for parts
of the figure that appear to be rectangles or
triangles and draw dotted lines to indicate how
the figure should be divided

7
• The Area Congruence postulate and the Area
Addition postulate make it possible to find the
area of complex composite figures by breaking
them down into simpler shapes and finding the
area of each shape

8
Find Area and perimeter
7 ft
3 ft
6 ft
4 ft
5 ft
9
Areas of composite figures by subtracting
• Find the area of the shaded region

10 in.
10 in.