Warm up

If the rate of tax is 7%, find the total cost of a television that sells for $750.

Boiled shrimp sells for $9.25 a pound. Write an equation that describes the total cost (T) is someone buys (P) pound of shrimp.

Tax: ($750) (0.07) = $52.50Final Cost: $750 + $52.50 = $802.50

T=$9.25P

Similarity – sides are proportional and angles are congruent.

8

6

10

4

3

5

Scale factor is 2 : 1

A tree is 32 feet tall. The tree casts a shadow of length 24 feet. If the shadow of a motel is 60 feet in length, how tall is the motel?

A tree is 32 feet tall. The tree casts a shadow of length 24 feet. If the shadow of a motel is 60 feet in length, how tall is the motel?

• Tree: 32

24

• Motel: x

60

feetx

x

xx

80

192024

)60)(32(2460

2432

A 42-foot tree casts a 27-foot shadow. At the same time, a flagpole casts a shadow 9 feet long. What is the flagpole’s height?

A 42-foot tree casts a 27-foot shadow. At the same time, a flagpole casts a shadow 9 feet long. What is the flagpole’s height?• Tree:

42

27

• Flagpole:x

9 feetx

x

x

x

14

37827

)42)(9(2727

9

42

Which of the following is a true statement?A. ∆PQR =∆STUB. ∆PQR ≈ ∆STUC. ∆PQR is both similar & congruent to ∆STUD. ∆PQR is neither similar nor congruent to ∆STU.

R

9

6

3

3 48

P Q

U

ST

Answer: D

||BE CD

32

40

54

x

B

A

C

D

E

24

172872

)54)(32(725472

32

x

x

x

x

||BE CD

6

12

x

7

B

A

C

D

E

21

1266

18

7

6

x

xx

The sheet of paper on the left is a reduced copy of the original. What is the length of the copy to the nearest tenth of an inch?

6 in.

8.5 in.

11 in.

x in.

8.7

665.8

11

6

5.8

x

xx