You will need
• - a sheet of paper;
• - handle;
• calculator;
• the pyramid with the specified parameters.
Instruction
1
Consider this in the task pyramid. Determine correct or incorrect polygon lying at its base. On the right, all sides are equal. The area in this case is equal to half the product of the perimeter to the radius of the inscribed circle. Find the perimeter by multiplying the side length l on the number of parties n, that is, P=l*n. To Express the area of the Foundation can be a formula of Ln=1/2P*r, where P is perimeter and r is the radius of the inscribed circle.
2
Perimeter and area of an irregular polygon are calculated differently. The sides are of different length. To calculate the perimeter is to add all the segments, limiting the basis. To compute the area run an additional build. Divide the irregular polygon in shape, the parameters of which you are aware of, and the area you can easily find using the most common formulas and trigonometric functions.
3
The lateral surface of a pyramid is the sum of all the lateral faces. The right pyramid of height falls in the center of the base regular polygon. For clarity, it is very helpful to build most of the height of the pyramid and one of its sides. The intersection of the second height to the bottom face connect with the center of the base. In any case, get a rectangular triangle, in which you need to calculate the hypotenuse, and the height of the side faces. Do so using your known parameters (for example, the height of the pyramid and the radius of the inscribed in the polygon of the base circle). 4
Knowing the height of the right side face of the pyramid, compute the lateral surface area. It is equal to half the product of the perimeter of the base to the height of the side faces, that is to calculate it by the formula SB=1/2P*h, where P is the already known perimeter, and h is the height of the side faces.
5
The calculation of the lateral surface of the irregular pyramid will require several time-consuming. It is equal to the sum of the areas of all lateral faces. Remember, what is the area of a triangle. It can be found by the formula S=1/2l*h, that is, polypropilenium the base of the triangle to its height.
6
Find the surface area of the pyramid. To do this, fold the already known base area and lateral surface.