Measuring Line Segments

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Measuring Line Segments

• Unit One
• (sec. 1.3)
• Lesson 02
• Koomens Klass

2
We can use the properties of a square to find its
area
or even its
side length
.
We can calculate the length of any line segment
on a grid by thinking of it as the side length of
a square!
Lets try this two ways . . .
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Example 1

• Use a ruler and a protractor (for 90o angles) to
  create a square with the segment PQ as one side
  length.

- the length of PQ is therefore the
square root of the area ?
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• Cut the square into four
• congruent triangles and
• a smaller square.

• Find the area of each
• triangle with the
• formula

What is the area of the smaller square?
Add all of these numbers together to get the
total area, then find the square root ? which
gives you the length of the line segment PQ
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• Use the existing grid to draw
• an enclosing square . . . Be
• sure to touch each corner.

Example 2

• Use the area formula to find
• the area of the larger square.

• The triangles formed by the large
• square are congruent. Find their
• area with the formula

• The area of the large square
• minus the area of the four
• triangles will leave you with

? the area of the original square ?

• Find the square root and you will have the length
  of each side
• segment!

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PRACTICE. . .
text p. 20 (7, 8, 9) p. 21
(11, 12)

• Show your work
• Check your answers

Homework worksheet pkg.