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Chapter 16. Plane Figures. By: Brittany Bolter (smartest girl EVER!). :]. Lesson one: Points, lines, and line segments. Line segment- Section of a line Bounded by two endpoints. Line segment. T. R. Say: line segment RT or Line segment TR. Write: RT or TR. Endpoints. Parallel-
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Chapter 16 Plane Figures By: Brittany Bolter (smartest girl EVER!) :]
Lesson one:Points, lines, and line segments • Line segment- • Section of a line • Bounded by two endpoints Line segment T R Say: line segment RT or Line segment TR Write: RT or TR Endpoints
Parallel- • Lines that are ALWAYS the same distance apart • They will NEVER touch E D Say: line BE is parallel to line CD B C Write: BE l l CD This symbol means “is parallel to”
Intersecting- • Lines the cross over each other H F J G E Say: line EF and line GH intersect at point J
Perpendicular- • two lines that form right angles T P Q V Say: line PQ is perpendicular To line TV Write: PQ TV This symbol means “Is perpendicular too”
Right Angle • an angle that has a measurement of 90 • Makes a square in the corner 90
Lesson two:Rays and Angles • Ray- • A line that has a starting point but no endpoint C Say: ray BC B Write: BC
Angle- • The amount of turning between two lines meeting at a common point • Formed by two rays with a common endpoint When naming an Angle, the vertex Is the middle letter. B C D
Sides- • One of the rays make up an angle Sides
Vertex- • The common endpoint of the angle • Where the two rays meet A ***When naming an angle, the Vertex is the middle letter. Example: angle ABC Vertex B C
Right angle- • An angle whose measurement is 90 • Makes a square in the corner
Obtuse angle • An angle greater than a right angle • Any angle between 90 and 180
Acute angle- • An angle less than a right angle • Any angle measurement less than 90
Straight angle- • Angle that forms a straight angle • Any angle that equal 180
Lesson three:measure angles • Degrees- • A unit for measuring the size of an angle • Written as
Protractor- • Instrument used to measure angles
How to use a protractor • Step 1: place the center mark of the protractor on vertex • Step 2: Align the 0 mark of one of the protractor scales with one ray of the angle to be measured