This is probably simple but can someone help me with this??

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

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.