**Points**

One of the most basic geometric figure is a point. All other geometric

figures are made up of a collection of points. The smallest dot you can

mark on your paper with a sharp pencil will give you an idea of what is

meant by a geometric point. Remember, a point is only an idea in our

mind; it is not a physical object and we regard it as having a position but

not size or shape.

**Lines**

**A line is the path describe by a
moving point. A straight line segment is formed when we use a ruler to join two
points, say A and B. We call the line segment AB or BA. A and B are called the
end-points.**

**The diagram below shows part of lines
with only one end-point and extending in only one direction. We call them rays.**

**A line is either straight or curved.
The diagram shows a curved line. A curved line is also called a curve.**

**Planes**

**A plane is a flat surface in which any two
points are joined by a straight line lying entirely on the surface. For example,
the ceiling of a room is a horizontal plane while the wall of the room is a
vertical plane.**

Examples of
planes

Angles

When two rays OA and OB meet at point O, an angle is formed. O
is also known as the vertex of the angle and OA and OB are the sides or arms of
the angles.

( drawn with geometer's sketchpad, u can download the trial version at __www.keypress.com/sketchpad
)__

There are many different kinds of angles. Here are a few basic ones:

An Acute angle is less than 90 degrees.

(angle B is an acute angle)

A right angle is equal o 90 degrees.

An obtuse angle is larger than 90 degrees but less than 180 degrees.

(Angle B is an obtuse angle )

A straight angle is equal to 180 degrees.

Other kinds of angles include :

Reflex angles, which are larger than 180 degrees but less than 360 degrees,
complementary angles, supplementary angles etc.