Such quadrangle at which two parties are parallel is considered a trapeze, and two others are not present. Height of a trapeze is called the piece which is carried out perpendicularly between two parallel straight lines. Depending on basic data it can be calculated differently.
It is required to you
- Knowledge of the parties, bases, average line of a trapeze, and also, optionally, its area and/or perimeter.
Instruction
1. One of ways to calculate area of a trapeze is the work of height and the average line. Let's say that there is an isosceles trapeze. Then height of an isosceles trapeze with the bases of an and b, the area of S and perimeter of P will be calculated so: h=2 x S / (P-2 x d). (see rice 1)
2. If only the area of a trapeze and its basis is known, then the formula of calculation of height can be brought out of a formula of the area of a trapeze of S = 1/2h x (a+b): h = 2S / (a+b).
3. Let's say there is a trapeze with the same data, as in figure 1. Let's carry out 2 heights, we will receive a rectangle at which 2 smaller parties are legs of rectangular triangles. Let's designate smaller rolls for x. It is by division of a difference of lengths between the big and smaller bases. Then on Pythagorean theorem the square of height is equal to the sum of squares of a hypotenuse of d and leg x. We take a root from this sum and we will receive h height. (fig. 2)