Introduction toEuclid’s Geometry
Question 1:
Exercise 3A
A theorem is a statement that requires a proof. Whereas, a basic fact which is taken for granted, without proof, is called an axiom.
Example of Theorem: Pythagoras Theorem
Example of axiom: A unique line can be drawn through any two points.
Question 2:
 Line segment: The straight path between two points is called a line segment.
 Ray: A line segment when extended indefinitely in one direction is called a ray.
 Intersecting Lines: Two lines meeting at a common point are called intersecting lines, i.e., they have a common point.
 Parallel Lines: Two lines in a plane are said to be parallel, if they have no common point, i.e., they do not meet at all.
 Halfline: A ray without its initial point is called a halfline.
 Concurrent lines: Three or more lines are said to be concurrent, if they intersect at the same point.
 Collinear points: Three or more than three points are said to be collinear, if they lie on the same line.
 Plane: A plane is a surface such that every point of the line joining any two points on it, lies on it.
Question 3:
 Six points: A,B,C,D,E,F
 Five line segments: , , , ,
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 Four rays: , , ,
 Four lines: , , ,
 Four collinear points: M,E,G,B
Question 4:

 and their corresponding point of intersection is R. and their corresponding point of intersection is P.
 , , and their point of intersection is R.
 Three rays are: , ,
 Two line segments are: ,
Question 5:
 An infinite number of lines can be drawn to pass through a given point.
 One and only one line can pass through two given points.
 Two given lines can at the most intersect at one and only one point.
 , ,
Question 6:
 False
 False
 False
 True
 False
 True
 True
 True
 True
 False
 False
 True