Answer:

Step-by-step explanation:
To find the surface area of a cone, one uses the following formula,

Where (r) is the radius of the base of the cone, and (h) is the height of the cone, (
) represents the numerical constant (3.1415...). In order for this formula to work, one needs the height of the cone. This can be found using the Pythagorean theorem. One can form a right triangle with the base's radius, the side length, and height of the cone, then solve for the height of the cone. The Pythagorean theorem states the following,

Substitute,

Simplify,

Inverse operations,

Now one can use the formula to find the surface area of a cone, substitute in the given values, and solve,

Substitute,


Answer:
First operation is Parathenses or Grouping. In this case, you need to use distrubtion to go past this operation
Step-by-step explanation:
The quadrant that it will be in is one
Answer:
Stratified sampling
Step-by-step explanation:
In the question, students are selected from subgroups of Sophomore, Junior, and Senior classes.
We are told that 49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348, and 481 students respectively.
This means that the sample numbers of 49, 34 and 48 students were selected in proportion to the subgroup sizes of 496, 348, and 481 students respectively.
Thus, due to the fact that subgroups were selected & that sample number of students were also selected in proportion to their respective subgroup sizes, this is therefore a stratified sampling.