What is 47 rounded up by a factor of 10

Given this information, which expression must represent the value of b?

1. a right triangle is graphed on a coordinate plane. find the length of the hypotenuse. round your answer to the nearest tenth. 2. use the angle relationship in the figure below to solve for the value of x. assume that lines a and b are parallel and line c is a transversal.

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem