Spieker Circle = Circumcircle of the Intouch Triangle of the Medial Triangle.

Spieker Circle = Circumcircle of the Mid-Arc Triangle of the Medial Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles.

The Spieker Circle is concentric to the Bevan Circle of the Euler Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles of the Orthic Triangle of the Excentral Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles of the Medial Triangle of the Anticomplementary Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles of the Anticomplementary Triangle of the Medial Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles of the Tangential Triangle of the Intouch Triangle.

The Spieker Circle is concentric to the Circumcircle of the Excentral Triangle of the Euler Triangle.

The Spieker Circle is concentric to the Bevan Circle of the Yff Central Triangle of the Medial Triangle.

The Spieker Circle is concentric to the Radical Circle of the Excircles of the Extangents Triangle of the Yff Central Triangle.

The Spieker Circle is concentric to the Inverse of the Spieker Circle in the Radical Circle of the Excircles.

The Spieker Circle is concentric to the Inverse of the Radical Circle of the Excircles in the Spieker Circle.

The Spieker Circle is congruent to the Nine-Point Circle of the Intouch Triangle.

The Spieker Circle is congruent to the Incircle of the Euler Triangle.

The Spieker Circle is congruent to the Nine-Point Circle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Circumcircle of the Medial Triangle of the Intouch Triangle.

The Spieker Circle is congruent to the Circumcircle of the Orthic Triangle of the Intouch Triangle.

The Spieker Circle is congruent to the Incircle of the Orthic Triangle of the Circum-Incentral Triangle.

The Spieker Circle is congruent to the Circumcircle of the Intouch Triangle of the Euler Triangle.

The Spieker Circle is congruent to the Circumcircle of the Medial Triangle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Circumcircle of the Orthic Triangle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Spieker Circle of the Anticomplementary Triangle of the Euler Triangle.

The Spieker Circle is congruent to the Spieker Circle of the Tangential Triangle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Circumcircle of the Euler Triangle of the Intouch Triangle.

The Spieker Circle is congruent to the Circumcircle of the Feuerbach Triangle of the Intouch Triangle.

The Spieker Circle is congruent to the Spieker Circle of the Euler Triangle of the Anticomplementary Triangle.

The Spieker Circle is congruent to the Circumcircle of the Mid-Arc Triangle of the Euler Triangle.

The Spieker Circle is congruent to the Circumcircle of the Euler Triangle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Circumcircle of the Feuerbach Triangle of the Mid-Arc Triangle.

The Spieker Circle is congruent to the Inverse of the Circumcircle in the Incircle.