Greg Markowsky's Problem for Parabola

Let A and B lie to the right of the axis OO' of a parabola with vertex O, with A closer to O than B. Draw OB, and draw AA' parallel to OO'. Let C be the intersection of AA' and OB. Choose D on OO' so that CD is perpendicular to OO'. Connect BD and AD. Show that ∠ADC = ∠BDC.

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Conic Sections > Parabola

The Parabola
Archimedes Triangle and Squaring of Parabola
Focal Definition of Parabola
Focal Properties of Parabola
Geometric Construction of Roots of Quadratic Equation
Given Parabola, Find Axis
Graph and Roots of Quadratic Polynomial
Greg Markowsky's Problem for Parabola
Parabola As Envelope of Straight Lines
Generation of parabola via Apollonius' mesh
Parabolic Mirror, Theory
Parabolic Mirror, Illustration
Three Parabola Tangents
Three Points on a Parabola
Two Tangents to Parabola
Parabolic Sieve of Prime Numbers
Parabolic Reciprocity
Parabolas Related to the Orthic Triangle

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