Projective frame

In mathematics, a projective frame in projective geometry is an (n + 2)-tuple of points in general position in the space ${\mathbb {R} }^{n+1}$ from which a projective space ${\mathbb {R} }P^{n}$ has been projected, one can take the first n + 1 points to form a basis, and the last to be the sum of the others.