Lesson on Scale Factor

Scale Factors and Scale drawings

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Multiple Choice

$$\Delta PQR\ is\ similar\ to\ \Delta STU$$  What side corresponds to side UT?

• PQ

• RQ

• QR

• QP

Multiple Choice

Scale Factor is a ratio comparing:

• the new value to the original value

• the original value to the new value

Multiple Choice

Triangle PQR is shown. Its original lengths are multiplied by 2.5. What are the new side lengths of P’Q’R’?

• PQ: 20, RQ: 42.5, RP: 37.5

• PQ: 16, RQ: 34, RP: 30

• PQ:4, RQ:8.5, RP: 7.5

Multiple Choice

Rectangle ABCD has been enlarged to form rectangle A’B’C’D’. What is the scale factor?

• 2

• 2.5

• 3

• 3.5

Reminder: You have independent practice

1. Classifying Triangles

2. Intro to Scale Factors

Open Ended

Exit Ticket: Triangle PRQ was enlarged to form triangle SUT. What is the scale factor?