Which of the following best describes the squaring property of equality?

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

The measure of an angle is 117°. what is the measure of a supplementary angle?