Does anyone know who Steggal was?
Antreas
PS: To readers interested in Euclidean Geometry:
The Steggal's Theorem states:
Let ABC be a triangle, and P a point (on the same plane).
If D,E,F are the projections of P on BC, CA, AB, and O, R the circumcenter,
circumradius respectively, then :
area(DEF) / area(ABC) = |R^2 - OP^2| / 4R^2
Corollary:
Let ABC be a triangle, and H, O, the orthocenter, circumcenter respectively.
Let A_1,B_1,C_1 be the projections of the O on the sides of the orthic
triangle, and A_2,B_2,C_2 the projections of the H on the sides of the same
triangle (:orthic). Then area(A_1B_1C_1) = area(A_2B_2C_2)
APH