The figure below shows a triangle with vertices a and b on a circle and vertex c outside it. side ac is tangent to the circle. side bc is a secant intersecting the circle at point x: the figure shows a circle with points a and b on it and point c outside it. side bc of triangle abc intersects the circle at point x. a tangent to the circle at point a is drawn from point c. arc ab measures 100 degrees and angle cba measures 42 degrees what is the measure of angle acb? 29° 8° 16° 21°