It is the circle's diameter
Not sure about a lie, but such a line is called the diameter.
A cardioid is a type of geometrical shape that is a type of limacon. A cardioid is formed when a circle is rolled around another circle creating a curved shape.
A mirror image of an object is said to have a line of symmetry
Tangent
tangent
It is the orthocentre.
The correct term for a line segment with both endpoints on a circle is a chord. The diameter of a circle is also a chord.
you're an idiot
tangent
Geometrical symmetry is a mathematical term for a shape that, if torn in half, can be mirrored and restored to the shape again.
symmetry
a tangent to the circle