Help thanks I appreciate it

Find the value of the variable and the length of each secant segment.

Which statement is true 1.the pythagorean theorem can be used to find the missing side of any triangle 2.the pythagorean theorem can be used to find the missing side of any polygon 3. the pythagorean theorem can be used to find the missing side of any right triangle 4.the pythagorean theorem can be used to find the missing side of any isosceles triangle

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)