+129845 If a tangent line and a secant line are drawn from a point outside a circle, the measure of the angle formed by the tangent and secant lines will equal 1/2 the difference of their intercepted arcs formed within the circle......more simply...
72° = (1/2) [ 200 - x] ° multiply both sides by 2
144° = 200” - x° add x° to both sides and subtract 144° from both sides
x° = [ 200 - 144]° = 56°
