Question

What is a plane surface?
A.A curved surface which extends in all directions is called a plane surface.
B.A line segment which extends in all directions is called a plane surface.
C.A cubic surface which extends in all directions is called a plane surface.
D.A flat surface which extends in all directions is called a plane surface.

Answer 1

We need to define a plane surface here. So, we will check if the options available satisfy the definition or not. A plane has no thickness,

Complete step-by-step answer:
We need to define what a plane surface is. We will generally check it with the definition of a plane surface in geometry.
The definition of a plane surface is: A two-dimensional and a perfectly flat surface which extends in all directions is known as a plane surface.
A plane extends infinitely in two dimensions with no thickness.
For e. g., a coordinate plane is an example of a plane surface. On the flat co - ordinate plane, there are two axes, the vertical y- axis and the horizontal x- axis. They intersect at a point called origin and it has its co- ordinates as (0, 0) and we denote it as O.
All planes are flat surfaces. If not, they are called curved surfaces.
Therefore, only option (D) satisfies the definition. Hence, option(D) is correct.

Note: For such types of questions, we should know the definitions of the terms for a better understanding of the concept. You may get confused between the given options as option (A) and option (B) are also quite near to the correct option if definition of plane surfaces is not considered.