WOLFRAM

DEMONSTRATIONS
PROJECT
Simson's Theorem
rotate
point
P
A
B
C
C
'
B
'
A
'
P
Let ABC be a triangle. Let P be a point on the circumcircle and let A', B', and C' be the feet of the perpendiculars from P to BC, AC, and AB. Then A', B' and C' are collinear.