-  projections pf a straight line
-  true length of a line
-  parallel lines , crossing lines , visible and invisible lines

projections of a line

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description  of  a  plane :

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-  projections of a plane
-  true length of a plane
-  projections of a circle

projections of a plane

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a point and  a  line outside a plane :

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-  a line parallel to a plane
-  a point of
-  a line perpendicular to a plane

a point and a line

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two planes :

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-  parallel planes
-  intersection of two planes
-  perpendicular planes

two planes

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an isometric view of a circle :

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-  isometric views of circles
-  isometric views of curved objects

circles in isometric views

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views of geometric objects :

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cilinders	conics	balls
piramids	prism

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sections :

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in a cilinder	in prism objects	in a conic
in a ball

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puncture points of lines :

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in a cilinder	in a prism	in a conic
in a ball

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prism objects with holes through them :

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objects with holes through them.

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penetration of prism into prism :

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penetrations in prisms

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penetration of prism into curved objects :

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penetration of a prism into a curved object :

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penetration of curved body into a curved one :

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penetrations in curved objects

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roofs :

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sloped roofs