USEFUL NOTES!!!

MATHEMATICS - FORM 1

POLYGONS

A) Recognising Polygons

A polygon is a plane figure with three or
more straight edges as its sides.

For example :-

(a)                       (b)
                 

(a) and (b) are polygons. 

(c)                        (d)
              

(c) and (d) are not polygons.


B) Names of Polygons
1. A polygon is named after the number of
    sides it contains. The following names
    are given to some common polygons.
    

2. The table below shows the number of
    sides, vertices and diagonals for some
    common polygons.

    

SYMMETRY

A) Determining and Drawing the Line(s) 
     of Symmetry of Shapes

1. An object is said to have a line of symmetry if it
   can be divided into identical halves when it is
   folded along that line.

For example :-

(a)                    
    

(b)
    



2. An object may have more than one line of
   symmetry.
    
    For example :-

    (a)                        
         


 TRIANGLES



     

A) Recognising Different Types of Triangles
 and their Geometric Properties
 

               

         (ii)
               

         (iii)
               
(b) The types of angles