I need help, and a step by step explanation! :)

90°

Step-by-step explanation:

There is no work. We know the right angle in the triangle and  the x are supplementary. Meaning, they add up to 180 degrees.  Therefore, 180-90 = 90. Think of it as a full triangle. If the 40 at the top was not half, but a full triangle, the 40 at the top would become 80. The 50 in the bottom left would mean there would be a 50 in the bottom right when you mirror the triangle. Therefore, you also need x to be 90 to make it a right triangle.

uhhh idk u yolo?

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.