Question 1199525
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The side AB of the triangle is vertical    x = c.


The side BC of the triangle is horizontal  y = e.


So, the triangle ABC is a right-angled triangle.


Its right angle is at vertex B;  its hypotenuse is AC (opposite to the right angle).


In any right-angled triangle, the center of the circumscribed circle is the mid-point of the hypotenuse.


It proves the statement.
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Solved.