MEANINGS / DEFINATIONS:

• Line segment : A line between two end points.
• Line : When a line segment extends indefinitely on both sides it is called a line.
• Intersecting lines  : Two  distinct lines meeting at a point are called intersecting lines
• Parallel lines : Two lines in a plane that have equal distance between them and do not meet are called parallel lines
• Ray : A ray is a position of line starting at a point and going in one direction endlessly
• Curve :  Any drawing  done without lifting the pencil may be called a curve
• Polygon : A polygon is a closed curve made up of line segments
• Angle: An angle is made up of two rays starting from a common  point
• Triangle : A three  sided polygon
• Quadrilateral : A four sided polygon
• Circle : A circle is a simple closed curve, that is not a polygon

What do u mean by the following:

Centre : A fixed point  that has equal distance from every point on the circumference  of a circle

Radius : A line segment drawn from the center of the circle to any point on the circle

Diameter : A line segment passing through the centre of the circle and ending on the two opposite sides of the circumference.

Chord:      A line segment joining any two points on the circle.

Arc :            A part of the circumference  of a circle

Sector:  It is the region in the interior of a circle enclosed by an arc on one side and a pair of  radii on the other two sides

Segment:  A region in the interior of a circle enclosed by a chord and an arc.

Circumference: It is the distance around a circle.