To celebrate World Wetlands Day, the Ministry of Environment and Tourism held a joint launch of the wetlands and ecotourism promotional material and biome posters as a demonstration of the country's commitment to wetlands and water con servation.
Surface: Perpendicularity is a fairly common symbol that requires the referenced surface or line to be perpendicular or 90Â° from a datum surface or line. Perpendicularity can reference a 2D line, but more commonly it describes the orientation of one surface plane perpendicular to another datum plane.urface: Perpendicularity is a fairly common symbol that requires the referenced surface or line to be perpendicular or 90Â° from a datum surface or line. Perpendicularity can reference a 2D line, but more commonly it describes the orientation of one surface plane perpendicular to another datum plane.
Notice the perpendicularity symbol. This is the correct way to identify this hole, since the hole itself now becomes the datum feature for other features to locate back to. That said, there are no GD&T police that will haul you to jail if you insist on using the position symbol.