GEOMETRY FOR PREP1 first term Fundamental concepts and definitions

GEOMETRY FOR PREP1 first term

Point: result from the intersection of two lines

A point has no dimensions

The line segment : it is set of points consisting of two distinct points and all points between them
, it has starting point and has ending point ,it has length

A B =B A  
The straight line : if we extended  the line segment from two direction indefinitely , we get The straight line
, it has not starting point and has not ending point
it has no length

A B = A C = B C =….

The ray :
it is the line segment extend from only one terminals without limit
, it has starting point and has not ending point
, it has no length

A B ≠ B A  ( they have different direction ) but A B = A C



Adjacent angle :
if they have a common vertex ,a common side and the other two sides are on opposite sides of this common side




Supplementary angle :
if the sum of their measures is 180



complementary angle : if the sum of their measures is90
The angle bisector: it is the ray that divides the angle into two halves  



The vertically opposite angle :
if they have a common vertex and each of the two sides of one is on a straight line with the sides of the other




Example:
(1)  73   is the complement of ……….

(2)  the angle 150    is the supplementary to ……….

(3)  25     is the complement of ……….

(4)  the angle 52  is the supplementary to ………
.
(5)  34     is the complement of ……….

(6)  the angle 149   is the supplementary to ……….