Assertion: polygon's angle | /r/HasProperty | right angles
Facets:
value: for both
type: PURPOSE
Source sentences:
text: A square is also a special quadrilateral because all four sides are congruent and all four angles are right angles.
text: All four angles are right angles for both.
text: Rectangle: all four angles are right angles.
text: Square (regular quadrilateral): all four sides are of equal length (equilateral), and all four angles are right angles.
text: whose all internal angles are right angles.