Form 1 MathematicsChapter 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 are the most basic concept in Geometry.

They are represented by a “X” and labelled by a Capital letter.

A point describes a location.

A line can be drawn by points

What is the difference between Line and Line Segment ( 線段 )?

Line segment has end-points

Naming a line: By 2 points on the line By a letter

Type of lines Straight line (直線 ) Curved line ( 曲線 )

Naming a plane: By corners (vertex 頂點 ) in either

clockwise or anti-clockwise order

By a Capital letter

We can learn a lot about geometry from the art of origami (摺紙 )

Let’s try to fold the paper:

Is the crease ( 摺痕 ) a point, a line or a plane?

Consider ABD and BCD are two different planes.

When two planes intersect each other (相交 ), they form a line.

We called it line of intersection

Let’s continue to fold the paper:

When two lines (AC and BD) intersect each other, they form a point.

We called it point of intersection

Think about the followings:

Is it possible to have two planes that do not intersect each other?

Is it possible to have two lines that do not intersect each other?

SHW (I) Hand in correction today!

OBQ Correction! (except the Bonus

question) 18 Jan (Fri)

CBQ 18 Jan (Fri)

Enjoy the world of Mathematics!

Ronald HUI