Form 1 Mathematics Chapter 6

 Lesson requirement  Textbook 1A  Workbook 1A  Notebook (and folder)  Before lessons start  Desks in good order!  No rubbish around!

 Geo-: land, earth (shape)  -metry: metre (measure)  Basic concepts of Geometry  Points 點  Lines 線  Planes 面  (Solids) 體

 Points 點  Lines 線  Planes 面

 When two lines intersect each other, they also form an angle between them.  The two lines are called the arms ( 射線 ) of the angle.  The point where the arms meet is called the vertex ( 頂點 ) of the angle.

 Name of angles  The middle letter “B” is the vertex!

 There are six types:

 Note: Any two line segments that meet each other form two angles.  We name  x as “  DAC”, and we name  y as “the reflex angle  DAC”.

 Name the angles below:

 When two lines in the same plane, but they do not intersect each other, they are called parallel lines ( 平行線 )  A pair of parallel lines is denoted by a pair of arrows ( 箭號 )  We write “AB // CD”

 When two lines in the same plane are intersecting at right angle (90  ), they are called perpendicular lines ( 垂直線 )  A right angle will be clearly shown in a pair of perpendicular lines  We write “AB  CD”

 Pages 233 – 234 of Textbook 1A  Questions 1 – 9  Pages 107 – 110 of Workbook 1A  Questions 1 – 8

 OBQ Re-Correction  Today!  CBQ Correction  23 Jan (Wed)  SHW (I)  23 Jan (Wed)

Enjoy the world of Mathematics! Ronald HUI