1. If one of the interior angles of a regular polygon is 90°, what isthe measure of the adjacent exterior angle?a. 180°b. 90°c. 120°d. 45°2. If one exterior angle of a rcgular polygon is 120°, what is themeasure of the adjacem interior angle?a. 60°b. 8)c. 100°d. 12003. If each interior angle in a certain regular triangle is 60°, what isthe sum of all interia angles?b. 480°c. 5400a. 360°d. 180°4. If the sum of the interior angle of a polygon is 360°, what is themeasure of each exterior angle?a. 120°b. 60°c. 90°d. 180°5. What is the measure of each exterior angle in a regular Octagon?a. 90°b. 45°C. 60°d. 30°6. How many sides does the polygon have, if the of the sum of theinterior angles is 1440°?a, 8b. 9c. 10d. 11​.