The statement cannot be proven because it is not true (or incomplete).
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.
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.
It depends on the angle of the plane of the cross section. If it is parallel to the cube's face (or equivalently, two adjacent edges) the cross section will be a square congruent to the face. If the plane is parallel to just one edge (and so angled to a face), the cross section will be a rectangle which will have a constant width. Its length will increase, remain at a maximum level and then decrease. If neither, it will be a hexagon-triangle-hexagon-triangle-hexagon (triangles when passing through a vertex).
A line that bisects a circle and goes through the center of it is the diameter.
In general 'to bisect' something means to cut it into two equal parts. The 'bisector' is the thing doing the cutting.In an angle bisector, it is a line passing through the vertex of the angle that cuts it into two equal smaller angles.Therefore it's in the definition.
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.
side
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.
Parallel light rays passing through a concave-flat lens converge towards the optic axis.
Given a triangle and a line, if the line passes through two sides of the triangle parallel to the third side, then it cuts the sides proportionally.l
5 A
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.
A concave lens will cause parallel light rays passing through it to diverge or spread out. This is because the lens is thinner in the middle than at the edges, causing the light rays to refract in a way that makes them spread apart.
vector
If you mean: y = -x-3 passing through point of (-1, 3) Then the equation of the parallel line is: y =-x+2
After passing through a diverging lens, a focal ray will diverge away from the principal axis of the lens.
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).