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1-2 Linear Measure You identified and modeled points, lines, and planes. Measure segments. Calculate with measures.
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1-2 Linear Measure

Feb 24, 2016

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1-2 Linear Measure. You identified and modeled points, lines, and planes. . Measure segments. Calculate with measures. Definition. Line segment – a measurable part of a line that consists of 2 points (end points) and all of the points between them. - PowerPoint PPT Presentation
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Page 1: 1-2 Linear Measure

1-2 Linear Measure

You identified and modeled points, lines, and planes.

• Measure segments.

• Calculate with measures.

Page 2: 1-2 Linear Measure

Definition

Line segment – a measurable part of a line that consists of 2 points (end points) and all of the points between them.A line segment is named by its 2 end points . It can be read right to left or left to right.

is read line segment AB or line segment BA.

The measure (length)of a line segment is written without the bar over the top of the 2 letters.

A B

Page 3: 1-2 Linear Measure

Length in Metric Units

A. Find the length of AB using the ruler.

The ruler is marked in millimeters.

Point B is closer to the 42 mm mark.

Answer: AB is about 42 millimeters long.

Page 4: 1-2 Linear Measure

Length in Metric Units

B. Find the length of AB using the ruler.

Each centimeter is divided into fourths.

Point B is closer to the 4.5 cm mark.

Answer: AB is about 4.5 centimeters long.

Page 5: 1-2 Linear Measure

A. 2 mmB. 1.8 mmC. 18 mmD. 20 mm

Page 6: 1-2 Linear Measure

Length in Standard Units

Each inch is divided into sixteenths. Point E is closer to the 3-inch mark.

A.

Measure in centimeters unless directions specify unit of measure.

Page 7: 1-2 Linear Measure

B.

Page 8: 1-2 Linear Measure

A.

A.

B.

C.

D.

Page 9: 1-2 Linear Measure

p. 15

Betweeness of points – for any 2 points , there is a real point between the 2 points.

A B C

Page 10: 1-2 Linear Measure

Find Measurements by Adding

Find XZ. Assume that the figure is not drawn to scale.

XZ is the measure of XZ. Point Y is between X and Z. XZ can be found by adding XY and YZ.

___

Add.

Page 11: 1-2 Linear Measure

A. 16.8 mm

B. 57.4 mm

C. 67.2 mm

D. 84 mm

Find BD. Assume that the figure is not drawn to scale.

B

C

D

16.8 mm

50.4 mm

Page 12: 1-2 Linear Measure

Find Measurements by Subtracting

Find LM. Assume that the figure is not drawn to scale.

Point M is between L and N.

LM + MN = LNBetweenness of pointsLM + 2.6 = 4SubstitutionLM + 2.6 – 2.6 = 4 – 2.6 Subtract 2.6 from each side.LM = 1.4 Simplify.

Page 13: 1-2 Linear Measure

Find TU. Assume that the figure is not drawn to scale.

TU

V3 in

A.

B.

C.

D.

in.

in.

in.

in.

Page 14: 1-2 Linear Measure

Write and Solve Equations to Find Measurements

ALGEBRA Find the value of x and ST if T is between S and U, ST = 7x, SU = 45, and TU = 5x – 3.

ST + TU = SU Betweenness of points

7x + 5x – 3 = 45 Substitute known values.

7x + 5x – 3 + 3 = 45 + 3 Add 3 to each side.

12x = 48 Simplify.

Draw a figure to represent this situation.

x = 4 Simplify.

Page 15: 1-2 Linear Measure

ST = 7x Given= 7(4) x = 4= 28 Multiply.

Answer: x = 4, ST = 28

Now find ST.

Page 16: 1-2 Linear Measure

p. 16

Congruent segments – segments that have the same measure.

The Geometry symbol for congruent is “≈”

Definition

Page 17: 1-2 Linear Measure

A. barbecuing and beachB. board games and museumsC. beach and picnicD. zoo and board games

LEISURE ACTIVITIES The graph shows the percent of adults who participated in selected activities. Suppose a segment was drawn along the height of each bar. Which categories would have segments that are congruent?

Page 18: 1-2 Linear Measure

Constructions

Constructions are a method of creating Geometric figures by using a pencil, compass, and straightedge.

Page 19: 1-2 Linear Measure

Drawings are created using measuring tools-rulers, protractors.

Sketches are created without the use of any tools.

Page 20: 1-2 Linear Measure

Copy a segment

1. Draw a segment to be copied.2. Draw a line on your paper with a dot near one end.3. Place the sharp point of the compass at one end point

of the segment.4. Open up the compass so the pencil matches the other

end of the segment.5. Without moving the compass, move it to the dot and

make an arc through the line.A congruent segment has been constructed.

Page 21: 1-2 Linear Measure

P. 18: 10-16 even, 22, 24, 28, 30, 46-50

Assignment 1-2