Give a definition for each of the following terms. Are there other terms that need to be defined first? What are they, and how might you define them?
(i) parallel lines
(ii) perpendicular lines
(iii) line segment
(iv) radius of a circle
(v) square.

AcademicMathematicsNCERTClass 9

To do:

We have to give the definition for each of the given terms and also the other terms that are needed to be defined first.

Yes, there are other terms and point which are needed to be defined first before we define the given terms.

Line: Line can defined as collection of points that has only length and no breadth. A line can be extended indefinitely on both sides.

Plane: a plane is a flat, two-dimensional surface that extends indefinitely in which geometric figures can be drawn.

Point: In geometry, point is a location represented by small dot, it has no length no breadth.

Circle: In geometry, a circle is a collection of all points in a plane which are at a constant distance (radius) from a fixed point (centre).

(i) In geometry, parallel lines can be defined as two lines in the same plane that are at equal distance from each other and never meet.

(ii) In geometry, perpendicular lines can be defined as two lines which intersect each other in a plane at right angles to each other.

(iii) In geometry, a line segment is a part of a line that is bounded by two distinct end-points, and contains every point on the line between its endpoints.

(iv) In geometry, radius of a circle can be defined as any point on the circumference of the circle to the center of the circle.

(v)  In geometry, a square is a quadrilateral in which all the four sides are equal and also has four right angles.

Updated on 10-Oct-2022 13:40:24