This polygon thing is all about triangles. If the polygon has 18 sides, it also has 18 central angles. 360/18 = 20. This means that each one of the triangles has a vertex angle of 20. We need to take this one triangle now and "pull" it out and isolate it cuz we only need to worry about 1, and we need to find the base measure of it for the perimeter, and the altitude of it for the apothem. It would be easiest then to separate this triangle in half and have it be a right triangle, and the vertex angle is now 10. If the vertex angle is 10 and this is a right triangle, then the 3rd angle by the triangle angle-sum theorem has to be 80. The side ACROSS from the 80 degree angle is the apothem and the info telling us that the radius is 13 now puts that 13 as the hypotenuse of our right triangle. We will use a trig identity relating this reference angle of 80 to the side across from it, "a", and the hypotenuse of 13.
and we get that that side measures 12.8, rounded. Now we have the apothem for the formula. Now we need the base measure of the right triangle. Use cos of 80 to find it:
ad we get the base measure of the right triangle is 2.25. But don't forget that this is only half the original triangle we pulled out, so the base of the "whole" triangle is 2.25 * 2 which is 4.5. If one side measures 4.5 and we have 18 of them, the perimeter for our formula is 81. Now let's put everything together in the formula to find the area for the polygon:
and we find that the area is 518.4
Answer:
well I'm sure if this is entirely correct but i would say it would be 12
Step-by-step explanation:
The surface area of a right rectangular prism is the sum of the areas of all six faces of the prism. To calculate the total surface area, you must calculate the area of each face, and then you add all six areas together. Each face is a rectangle. As a shortcut, you really only need to find at most three areas since each two opposite faces are congruent rectangles and have equal areas. Since the area of a rectangle is length times width, and they are both measured in linear measurements, such are meters or feet, the area of each face is in square meters or square feet. The total area is also measured n square meters or square feet. If you are painting a room, including all walls, the floor and the ceiling, it would be helpful to know the total surface area to calculate the amount of paint needed. Also, if you are wrapping a box that is shaped like a right rectangular prism, the the total surface area will tell you how much area of wrapping paper you need.
The volume of a right rectangular prism is the amount of three-dimensional space it occupies. To calculate it, you multiply the length by the width by the height. Since length, width, and height are linear measures, with units such as meters or feet, the volume is a cubic measure measured in cubic meters or cubic feet. If you have a certain volume of an item that you need to put in a box, then by knowing how to calculate the volume of the box, you can tell what size box you will need.
There are 5280 feet in a mile, if thats what youre asking..?
idk if this was helpful or not, sorry :/
Answer:Y=3x+7.25
Step-by-step explanation:
