What is the proper procedure for removing a domain controller from active directory?

You would do the following  remove Active Directory from a domain controller that is not the last domain controller in the domain, you do not have to provide credentials. However, you must be logged on as a member of either the Domain Admins group or the Enterprise Admins group.

Use the formulas for the area of a triangle and the area of a rectangle for both figures. The bases are the tops and bottoms of the figures and the lateral sides are the sides not including the top or bottom. It’s basically just finding the areas of each side and adding them all up to find the surface area. Volume is finding the area of the base, using the triangle area formula, and multiplying that by the height of the figure
Hope this helps!