MathDB

Let

O

be the center and

[AB]

be the diameter of a semicircle.

E

is a point between

O

and

B

. The perpendicular to

[AB]

E

meets the semicircle at

D

. A circle which is internally tangent to the arc \overarc{BD} is also tangent to

[DE]

and

[EB]

K

and

C

, respectively. Prove that

\widehat{EDC}=\widehat{BDC}

Problem Statement