Does anybody know about this I'm stuckes it's about angles

Answer:
alpha = 25°
Step-by-step explanation:
The picture indicates a rectangle.
Alpha is in a straight corner of 90 °, so...
65 + alpha = 90
subtract 65 left and right of the = sign.
65 - 65 + alpha = 90 - 65
0 + alpha = 90 - 65
alpha = 25°