Assertion: parabola's property | /r/HasProperty | focal
Facets:
Source sentences:
text: If the directrix and focus are given, a parabola can be constructed using the focal property, as shown at the right.
text: Since ER = FR, R must be a point on the parabola, from its focal property.
text: The parabola is generated as a direct consequence of its focal property in this construction.