What is the definition of complicated interconnections

What is the length x of the side of the triangle below? (hint: use the cosine function)

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.

Positrons are spontaneously emitted from the nuclei of