Please explain step by step I dont get it.

The answer to this is 47.5 degrees.

Step-by-step explanation:

To find the missing angle of a triangle, you must first understand what the known angles are. For this triangle you have 2 angles already known, the 42.5 degree angle, and the 90 degree angle. An angle will always be 90 degrees if it has that little square. When a triangle has a single 90 degree angle, that triangle will be a right triangle. the following angles will add up to 90 degrees, and so you can just take 90 and subtract 42.5 from it, to find the missing angle length of 47.5 degrees.

Hopefully this answers your question fully, if you need any more help just comment on this :)

i found two solutions,   n = 2 • ± √3 = ± 3.4641

step-by-step explanation: