This document contains notes from a math lesson on computing actual areas from scale drawings. It includes examples of finding the scale factor between drawings and actual objects, then using that scale factor to determine the actual areas. The notes provide step-by-step workings and solutions for three examples, and ask students to confirm if their actual area findings match the example results. It also poses closing questions about using scale factors to find real-world areas from scale drawings.

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Computing Actual Areas
from a Scale Drawing.
Do Now: Lesson 18 Exit Ticket
10/15/15Module 1, Lesson 19
HW: Lesson 19 Problem Set #4
QUIZ 2 Monday

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Problem Set Solutions S.82

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Use the diagrams below to find the scale factor and then find
the area of each figure.
Example 1:

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Use the diagrams below to find the scale factor and then find
the area of each figure.
Example 2:

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Use the diagrams below to find the scale factor and then find
the area of each figure.
Example 3:

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Does the actual area you found reflect the results we found from
Examples 1–3? Explain how you know.

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2
1
1
2
2
2 1
2
in.in.
in. in.

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Closing:
1.) When given a scale drawing, how do we go about finding
the area of the actual object?
2.) Describe a situation where you might need to know the
area of an object given a scale drawing or scale model.

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