This is a 45-45-90 triangle or a right triangle created by the sides.
Because of this being a right triangle and 45 degrees being given already for one angle you would add 90 and 45 which will give you 135. You would subtract 135 from 180 because all the angles of a triangle add up to 180°. 180-135=45. X=45°
The formula to calculate the total surface area of a cylinder is given as, the total surface area of cylinder = 2πr(h + r), while the curved surface area of cylinder formula is, curved/lateral surface area of cylinder = 2πrh, where 'r' is the radius of the base and 'h' is the height of the cylinder.
