Read the following statement : ''A square is a polygon made up of four line segments, out of which, length of 3 line segments are equal to the length of forth one and all its angles are right angles''. Define the terms used in this definition which you feelnecessary. Are there any undefined terms in this ? Can you justify that all the angles and sides of a square are equal?

Read the following statement : ''A square is a polygon made up of fou

1.	Read the following statement : ''A square is a polygon made up of four line segments, out of which, length of 3 line segments are equal to the length of forth one and all its angles are right angles''. Define the terms used in this definition which you feelnecessary. Are there any undefined terms in this ? Can you justify that all the angles and sides of a square are equal?
Answer» Solution :For the desired problem, we need to define the following terms: Polygon : Any closed figure made up of three or more line segments. Line segments : Part of a line with twoend points. Line : UNDEFINED term. Point : Undefined terms. Ray : Part of a line with one end point. Right angle : Angle whose MEASURE is `90^(@)`. Now, from Euclid's fourth postulate, ''all right angles are equal to one another'' and in a square, all angles are right angles, therefore all angles are equal. From Euclid's FIRST axion ''things which are equal to the same thing are equal to one another'' and it is given that 3 line segments are equal to forth line SEGMENT. Therefore, all the 4 sides of a square are equal.