Pls help with this question

Which term best describes the association between variables a and b

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Aline is perpendicular to another line m2= (-1/m1), where m1 is the slope of the original line and m2 is the slope of the perpendicular line. which of the following equations represents the line that passes through the point (-2,1) and is perpendicular to the line below?