An upright circular cone with radius of base area 
and height 
.
Calculate the total surface area of the cone.
Draw a regular four-sided pyramid to a given cone (the base surface of the pyramid is inscribed to the base surface of the cone). Calculate the volume of this pyramid.
We draw a sphere for a given cone. Calculate its radius.
The given cone is cut by two mutually perpendicular planes passing through the axis of the cone so as to divide it into four equal parts. Calculate the area of one part. The result should be accurate. (The axis of the cone is a line passing through its apex and the center of the base plane.)
