An angle with the vertex ON the circle can look like this: vertex on the circle Find the angle measures 120o º º 200o The vertex of an angle can be INSIDE the circle but NOT on the center Center The vertex of an angle can be INSIDE the circle but NOT on the center Center not center To find the angle, add the arc of the angle and the arc opposite that arc add those arcs and divide by 2 40o 160o 160 + 40 = 200 ÷ 2 = º º Determine the angle measures marked as "x" and "y". x = º 10o 6o x 100o y = º y 10o If the vertex of the angle is OUTSIDE the circle subtract the two arcs inside the angle then divide by 2 115o 35o x x = º Find the angle measures 200o 60o º 180o 70o º Solve for the missing arc measure. 260o 80º º |