What basic trigonometric identity would you use to verify that csc x sec x cot x = csc^(2)x

Tell me how you got the it use the figures to answer questions 1and 2. in each diagram, line k is parallel to line l, and line t intersects lines. 1. based on the diagrams, what is the value of x? 2. how would you verify your answer for x?

10 points? me . its important ‼️‼️

Solve the triangle. a = 21°, c = 105°, c = 5