# The Area of a Triangle, its Circumradius, and the Perimeter of its Orthic Triangle

The Area of a Triangle, its Circumradius, and the Perimeter of its Orthic Triangle

Let ABC be an acute triangle and A'B'C' be its orthic triangle (the triangle formed by the endpoints of the altitudes of ABC). Let be the perimeter of A'B'C', be the circumradius of ABC, and be the area of ABC. Then .

p

R

α

p×R=2α