The only one ☝️ I cant get

In the diagram below what is the approximate length of the minor arc ab

12 point are triangles pqr and stu congruent? what is the congruency that proves they are congruent? what is the perimeter of triangle pqr?

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.