The boundaries of surfaces are lines.

Explanation:
In geometry, a surface is a two-dimensional object that does not have any thickness. It can be thought of as the boundary or exterior part of a solid object. Surfaces can be flat or curved, and they can have different shapes and sizes.

When we talk about the boundaries of surfaces, we are referring to the edges or lines that define the shape of the surface. These lines mark the transition from one surface to another or from a surface to an open space.

Examples:
To better understand this concept, let's consider a few examples:

1. A rectangular prism: The surface of a rectangular prism is made up of six rectangular faces. The boundaries of each face are the four lines that form the edges of the rectangle.

2. A sphere: The surface of a sphere is curved and continuous. However, if we were to cut the sphere, the boundary of the cut surface would be a circle. This circular line marks the edge of the surface.

3. A pyramid: The surface of a pyramid is composed of triangular faces. The boundaries of each face are the three lines that form the edges of the triangle.

4. A cylinder: The surface of a cylinder consists of two circular faces and one curved side. The boundaries of the circular faces are the circular lines, while the boundary of the curved side is a curved line.

Conclusion:
In conclusion, the boundaries of surfaces are lines. These lines define the shape and edges of the surface, whether it is flat or curved. Understanding the boundaries of surfaces is essential in geometry as it helps us analyze and classify different shapes and objects.

That is incorrect in book page no 62 you can see the boundaries of the surfaces are curves