From
Altitude
It has 8. Each passes through the centre. Four pass through vertices, four pass through the mid-points of opposite sides
median
perpendicular
If you perform an angle bisector on an angle in a triangle, then it will go through the midpoint of the opposite side.
A line through the vertex and the side opposite - nothing more. There need not even be a side opposite - as is the case with a square!
If you mean the opposite of passive transport, like through a membrane, the opposite is active transport.
Evaporation is the opposite of condensation.
The segment that passes through a vertex and is perpendicular to the opposite side is called the altitude of the triangle.
If you mean opaque then the opposite of it is transparent.
Opaque
There is no single-word opposite of "permeate," which means to spread throughout an area or to pass through a membrane.
The opposite of translucent is opaque. Opaque materials do not allow light to pass through them, whereas translucent materials allow some light to pass through but not enough to see clearly through them.
vector
The visual and optical opposite of transparent is "opaque."Metaphorically, the description of motives as transparentwould have the opposites unclear or hidden.
The opposite of recrystallize is amorphize, where a crystalline substance is transformed into an amorphous form, such as through melting and rapid cooling.
The opposite of opencast mining is underground mining, where minerals are extracted beneath the earth's surface through tunnels and shafts rather than through open pits.