Can someone please help me with this?

There is a sleeping line, the ladder lying flat on the floor and the man lying on the floor.

What you see is described as HORIZONTAL.

A sleeping line is nothing but a horizontal line.

A ladder lying flat is the same as a ladder lying horizontally.

A man lying flat on the floor is the same as a man lying horizontally on the floor.

Horizontal is the opposite of vertical. In geometry, we use the words vertical and horizontal for standing and sleeping respectively.

The line at which the earth’s surface and the sky appear to meet is called the horizon. Anything parallel to the horizon is called horizontal.

Explanation:

electrical to thermal

conduction, convection, radiation