Im not really sure how to do this and how to find the answer. I think it's supposed to equal 180° but I don't get the (2x+1) part.

Answer:
45° (if you need to also find x, it's 22)
Step-by-step explanation:
First of all, you need to remember that all triangles are equal to 180°. By examining the triangle, you already know two of the angles: 45° and 90° (you can tell it is a right triangle because of the box in the bottom-right corner). Since you have two of the three angles, you can deduce that the unknown angle is 45° (45 + 90 + 45 = 180).
(Just in case you need to also find x, just write it as an equation and solve for x.)
Hope this helps!!!❤️