The degree of the XZW, the tangent-chord angle is 128. 1/2 of the 256 is 128. the answer to this query which is looking what is the measure of the XZW is 128. Tangent -chord theorem is likewise known as alternate segment theorem states that any circle, the angle among a chord and a tangent thru one of the end factors of the chord is identical to the perspective inside the exchange segment.