Assertion: ellipse's point | /r/HasProperty | $f_1f_2
Facets:
Source sentences:
text: The mid-point of the segment $F_1F_2$ is called the centre of the ellipse.
text: There are two special points $ F_1,F_2 $ on the ellipse's major axis, on either side of the center, such that the sum of the distances from any point of the ellipse to those two points is constant and equal to the major diameter $ 2a $ .