What Have We Discussed?

1.A point determines a location region and is usually denoted by a capital letter.

2. A line segment corresponds to the shortest distance distance longest distance between two points. The line segment joining points say, A and B is denoted by AB.

3. A line is obtained when a line segment like AB is extended on both sides on one side indefinitely; it is denoted by AB or sometimes by a single small letter like l.

4. A raycurve is a portion of line starting at a point and going in one direction endlessly.

5. Any figure drawn without lifting a pencil may be called a curve. In this sense, a line is also a .

6. A simplecurve curve is one that does not cross itself.

7. Curves are of types- open and closed.

8. An angle is made up of two rays starting from a common end point. The common end point is called and the two rays are arms of the angle.

9. Every angle divides the plane as interior, exterior and boundary of the .

10. A triangle is a simple closed figure bounded by line segments.

11. A trianglecircle has three vertices, three sides and three angles.

12. A triangle with its boundary and interior is called the region.

13. A quadrilateral is a simple closed figure bounded by line segments. It has four vertices, four sides, four angles and two diagonals.

14. A circletriangle is simple closed curve, where each point on the boundary is at an equal distance from the centre. The fixed distance is the radius.

15. A part of a circle is an arc and the total length of the circle is called its .

16. A chord of a circle is a line segment joining any two points on the circle. Diameter is also a chordray.

17. A diameter of a circle is double the .

18. A with its boundary and interior together is a circular region.

19. The region in a circle bounded by two radii and the arc is called sectorradius.

20. The region in a circle bounded by a chord and the arc is called a of the circle.

21. A semi circle is of the circle. Each diameter divides a circle into two semicircles.