AC is a tangent to the circle below at point B. Calculate the sizes of angle x, angle y and angle z. Justify each of your answers. .
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[tex]y=78^{\circ}[/tex] (alternate interior angles theorem)
[tex]x=78^{\circ}[/tex] (alternate segment theorem)
[tex]z=24^{\circ}[/tex] (angles in a triangle add to 180 degrees)