The angled lines used to indicate the surfaces which are cut by the imaginary cutting-plane are called:

Section lines

Step-by-step explanation:

Sectioning is the process of cutting a surface by an imaginary plane, the view of the surface that is cut is shown in the section view.

Section lines are used to indicate where an imaginary cutting plane cuts a material. The imaginary cut is then represented using section lines which are usually thin, crosshatched.

Section lines shows the surface that have been cut by the cutting plane. There are different ways of sectioning such as full section, half section, off set section and so on

just take the area of the square and then the area of the circle then subtract the circle area from the squares area

step-by-step explanation:

$5.41

step-by-step explanation:

$20 - $14.51 = $5.49.