Area formulas include rectangular area formula, square area formula, sector area formula, circular area formula, bow area formula, diamond area formula, triangle area formula, trapezoid area formula and other graphic area formulas.
1. common area theorem
The area of a graph is equal to the sum of the areas of its parts; The areas of two congruent figures are equal; Triangles, parallelograms and trapezoids with equal bases and heights have equal areas.
The area ratio of triangle, parallelogram and trapezoid with equal base (or equal height) is equal to the corresponding height (or base) ratio; The area ratio of similar triangles is equal to the square of similarity ratio; The ratio of the area of an equilateral or complementary triangle is equal to the ratio of the product of two sides of the equilateral or complementary triangle; The area ratio of an equilateral parallelogram is equal to the ratio of the products of two equilateral sides.
2. Calculation flow formula of construction area
The calculation flow formula of house area is: room area = length × width; In addition, for room construction area = room indoor area+pool area; Room interior area = room interior usable area+room interior wall area+room balcony area.
3. Room area measurement is normal.
The area written on the property certificate or contract is the total area when we buy it, including the pool, wall and other areas; Total actual use area-wall construction area-shared public construction area;
4. Interior wall area
Including the interior wall of the room, the enclosure wall of the peripheral space, the use wall, the public wall, etc. Among them, half of the public wall is calculated by horizontal projection, and all calculations are used for non-* *; The closed balcony calculates the total construction area according to the horizontal projection, and the concave-convex balcony calculates half the construction area according to the horizontal projection;
5. Calculation of public building area
Buildings that use or sell the latest seats independently should not be included in the best public building area, such as basements, carports and civil air defense basements. The calculation coefficient of public building area should be: sharing coefficient of public building area = sum of public building area/interior building area; Interior construction area x allocation coefficient of public construction area = reasonable allocation of public construction area of purchased house.