I need help ASAP (will give brainliest)

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?

Translate this phrase into an algebraic expression. 21 more than twice goran's savings use the variable g to represent goran's savings. need to know fast.

The areas of two similar triangles are 72dm2 and 50dm2. the sum of their perimeters is 226dm. what is the perimeter of each of these triangles?