Write the number 360, but use only three sevens and mathematic operators

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?

Name each raycalculation tip: in ray "ab", a is the endpoint of the ray.

The reflexive property of congruence lets you say that ∠pqr ≅