11.3 perimeters and area of similar figures similar polygons
TRANSCRIPT
11.3 Perimeters and Area of Similar Figures
Similar Polygons
Remembering Similar Polygons
Similar polygons have all the Angles congruent and the Sides have the same ratios. (like these three houses)
Remember this Theorem
If two polygons are similar (equal angles and corresponding sides in ratios), then the perimeters ratio is the same as the scale factor.
Perimeters are 24:16 same ratio as 3:2 for the sides
Theorem
If two polygons are similar (equal angles and corresponding sides in ratios), then the Area ratio is the same as the scale factor squared. (in the regular hexagons)
6
2
1:91:3
1:32:6
22
RatioArea
RatioPerimeter
Find the Area and Perimeter
The given figures are similar
8 5
60
32
Area
Perimeter
Area
Perimeter
How would you find the area?
Find the Area and Perimeter
The given figures are similar
8 5
60
32
Area
Perimeter
Area
Perimeter
?:6025:645:8
?:325:8
22
RatioArea
RatioPerimeter
Find the Area and Perimeter
The given figures are similar
8 5
60
32
Area
Perimeter
Area
Perimeter 20
208
160
325832
5
8
P
PP
Find the Area and Perimeter
The given figures are similar
8 5
60
32
Area
Perimeter
4375.23
20
Area
Perimeter
4375.2364
1500
60256460
25
64
A
AA
Homework Page 679-680# 8 – 24,
39 - 41