I'm not 100% sure about part A, but it looks like a regular hexagon is being constructed. Though some marks seem to be missing. Again I'm not fully certain.
But I'm sure about parts B and C.
For part B, this is showing the construction of the perpendicular bisector to segment AB. The perpendicular bisector is perpendicular to the given segment and it cuts the given segment AB in half.
In part C, a line is being constructed to go through point R such that it is parallel to line PQ.