9
a/b a 2 /b 2
a/b
a2/b2
Practice p632 #1113, 17, 18, 2123, 35, 44, 45
p638 #1, 2
1696
16 24 3636 54 48
2/33/4
2/33/4
4/99/16
12 1615 20
9 12
6
4
5 in
7 in
Given: Regular Octagons
What is the scale factor?
What is the ratio of their perimeters?
What is the ratio of their areas?
Given: Similar Trapezoids
What is the scale factor?
What is the ratio of their perimeters?
What is the ratio of their areas?
What is the scale factor of these regular pentagons?
What is the ratio of their areas?
perimeter = 7 cm
perimeter = 21 cm
What is the scale factor of these regular docecagons?
What is the ratio of their perimeters?
Area = 25 m2
Area = 144 m2
Given: Similar Parallelograms
What is the ratio of the perimeters?
Area = 18 in2
Area = 98 in2
Area = 2π cm2
Area = 200π cm2
What is the ratio of the circumferences?
Scale Factor
ab
Perimeter
a1 P1
b1 P2=
Area
a2 A1
b2 A2=
Volume
a3 V1
b3 V2=
5 in7 in
Find the area of the smaller octagon to the nearest tenth.
A = 236.6 in2
Scale Factor
ab
Perimeter
a1 P1
b1 P2=
Area
a2 A1
b2 A2=
Volume
a3 V1
b3 V2=
Scale Factor
ab
Perimeter
a1 P1
b1 P2=
Area
a2 A1
b2 A2=
Volume
a3 V1
b3 V2=
The scale factor of two similar floors is 5 : 3. It costs $336 to tile the larger floor. At that rate, how much would it cost to tile the smaller floor?
Practice p638 #7, 1017, 1921, 36, 39
