Geometry (Lines)

lines, segments, rays, points, , intersecting, , & perpendicular

 “A point is an exact location in space.  It has no length or width.”  Points have names; represented with a Capital Letter. – Example: A a Lines

 “A is a collection of points going on and on infinitely in both directions. It has no endpoints.”  A straight line that continues forever  It can go – Vertically – Horizontally – Obliquely (diagonally)  It is identified because it has arrows on the ends.  It is named by “a single lower case letter”. – Example: “line a” A B C D Line Segment

 “A line segment is part of a line. It has two endpoints and includes all the points between those endpoints. “  A straight line that stops  It can go – Vertically – Horizontally – Obliquely (diagonally)  It is identified by points at the ends  It is named by the Capital Letter End Points – Example: “line segment AB” or “line segment AD” C B A Ray

 “A ray is part of a line. It has one endpoint and continues on and on in one direction.”  A straight line that stops on one end and keeps going on the other.  It can go – Vertically – Horizontally – Obliquely (diagonally)  It is identified by a point at one end and an arrow at the other.  It can be named by saying the endpoint first and then say the name of one other point on the ray. – Example: “Ray AC” or “Ray AB” C

Angles A B

 Two Rays That Have the Same Endpoint Form an . This Endpoint Is Called the Vertex.  Angles Are Found Wherever Lines and Line Segments Intersect.

C A

Angles A B

 An Angle Can Be Named in Three Different Ways by Using – Three Letters to Name, in This Order, Example: “Angle BAC”  A Point on One Ray,  The Vertex, and 1  A Point on the Other Ray; – One Letter at the Vertex; “Angle A” – Or a Number Written Inside the Rays of the Angle. Example: “Angle 1” C

Angles A B

 There are 3 types of angles – Acute Angle: Smaller than 90 degree opening C

A B – Obtuse Angle: Larger than 90 degree opening

C A B – Right Angle: 90 degree opening C

A B Intersecting Lines

 “Intersecting lines are lines that cross and have one point in common.”  Example: “Line AC intersects Line DE at Point B”

D C B

A E Perpendicular Lines

 “Perpendicular lines are special intersecting lines that form right angles (square corners) where they intersect.” Parallel Lines

 “Parallel lines are lines that lie on the same flat surface () and never cross.  Parallel lines are always the same distance apart and do not share any points.”  Example: “Line AB is Parallel to Line CD”

C D

A B Name That Line!

1. 3. a A B C D

A C 5. 2.

A B 4.

C B A Name That Angle!

7. 6. C C A B A B 8. C

A B Name The Type of Lines!

11. 9. D C B A E

10. Now, Draw Your Own Lines.

 Point  Intersecting Lines  Line  Perpendicular  Line Segment Lines  Ray  Parallel Lines  Angles – Acute – Obtuse – Right