What is the length of the radius of the circle whose center is the origin and that passes through
the point (-5, -12)?
(1) 7
(2) 13
(3) V13
(4) 119

Find the value of the cosine for angle a

Me because some of question i don’t understand

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.