ArcGIS Developer Help (ESRI.ArcGIS.Geometry) 

IConstructPoint Interface
Provides access to members that construct a point using other geometries and measures.
Members

Name 
Description 

ConstructAlong 
Constructs a point distance units along the input curve. 

ConstructAngleBisector 
Constructs a point on the bisector of the angle (from, through, to). When useAcuteAngle is false, the sign of distance will select a point right or left of (from, through, to). Otherwise, the sign of distance will select the acute/obtuse point. 

ConstructAngleDistance 
Constructs a point at a specified angle (in radians) from the horizontal axis and a specified distance away from the input point. 

ConstructAngleIntersection 
Constructs the point of intersection between two lines defined by the input points and angles (in radians). 

ConstructDeflection 
Constructs a point in the polar coordinate system defined by baseLine and its 'from' point. The angle is in radians. 

ConstructDeflectionIntersection 
Constructs the point of intersection of two rays with origins at the endpoints of the base line and the specified angles (in radians). If onRightSide is true, this work will be done to the right of the base line, otherwise to the left. 

ConstructOffset 
Constructs a point distance units along the input curve and offset units perpendicularly away from it. 

ConstructParallel 
Constructs a point distance units from start, parallel to the tangent at the point nearest to start on the (extended) segment. 

ConstructPerpendicular 
Constructs a point 'distance' units from p and lying along the line normal to base and passing through p. 

ConstructThreePointResection 
Constructs the point of observation from which two signed angles between three points were measured; returns an angle which can help establish the confidence of the observation location: A small angle indicates greater uncertainty in the location. 
Classes that implement IConstructPoint
Classes 
Description 
Point 
A two dimensional point, optionally with measure, height, and ID attributes. 