For question 1, it is important to know the vertical angles are angles that are equal to each other because they are congruent and are "across" from each other when two lines intersect. Therefore, you can set an equation where one side is equal to the other as you are solving for x, which would be 2x=x+30. You may then solve this equation like any other equation based on mathematical properties and operations, whereas this is how you may do question #1.
The total surface area of a solid is the sum of the areas of all of the faces or surfaces that enclose the solid, the lateral surface area of a solid is the surface area of the solid without the bases
