median
perpendicular
A median of a triangle is a line or segment that passes through a vertex and bisects the side of the triangle opposite the vertex.
Altitude
If you mean which triangle has at least two lines of symmetry, I can answer your question: an equilateral triangle has three lines of symmetry-- one passing through the center of each side and through the opposite point, perpendicular to the side.
If you perform an angle bisector on an angle in a triangle, then it will go through the midpoint of the opposite side.
Every triangle has three medians, just like it has three altitudes, angle bisectors, and perpendicular bisectors. The medians of a triangle are the segments drawn from the vertices to the midpoints of the opposite sides. The point of intersection of all three medians is called the centroid of the triangle. The centroid of a triangle is twice as far from a given vertex than it is from the midpoint to which the median from that vertex goes. For example, if a median is drawn from vertex A to midpoint M through centroid C, the length of AC is twice the length of CM. The centroid is 2/3 of the way from a given vertex to the opposite midpoint. The centroid is always on the interior of the triangle.
No way! An easy example is the centroid and circumcenter of a right-angle triangle. Circumcenter will be exactly on the middle of the hypotenuse which obviously cannot be the centroid. Centroid is the point where all three lines are connecting all the three vertices and the middle of the line opposite the respective vertex. Circumcenter is the center of the circle passing through all the vertices. As it is known, a right-angle triangle will always fall within a semicircle, meaning the circle center will always be on the middle of the hypotenuse.
a side
and is perpendicular to the opposite side.
A median of a triangle is a line segment joining a vertex to the midpoint of the opposite side. Altitude of a triangle is a straight line through a vertex and perpendicular to the opposite side or an extension of the opposite side.
perpendicular
side
Altitude.
A median of a triangle is a line or segment that passes through a vertex and the midpoint of the side opposite that vertex. The median only bisects the vertex angle from which it is drawn when it is an isosceles triangle.
A median of a triangle is a line or segment that passes through a vertex and bisects the side of the triangle opposite the vertex.
The segment that passes through a vertex and is perpendicular to the opposite side is called the altitude of the triangle.
Only in an equilateral triangle will bisectors of the three angles bisect the opposite sides. In an isosceles triangle, only the bisector of the one different angle will bisect the opposite side (between the identical angles).