Answer:
Tangent line states that a line in the plane of a circle that intersect the circle in exactly one point.
Common external tangent states that a common tangent that does not intersects the line segment joining the centers of circle.
Common internal tangent states that a common tangent that intersects the line segment joining the centers of circle.
Circumscribe polygon states that a polygon with all sides tangent to a circle contained within the polygon.
Therefore:
A polygon with all sides tangent to a circle contained within the polygon = Circumscribe polygon
A common tangent that intersects the line segment joining the centers of circle = Common internal tangent
A common tangent that does not intersects the line segment joining the centers of circle = Common external tangent
a line in the plane of a circle that intersect the circle in exactly one point = Tangent line