The procedures will depend on what the shape is and what information you have about the shape. Furthermore, you may wish to check that it is actually the apotheosis that you want and not the apothem.
If you are calculating the area of a rectangle, it is length times width. You are not multiplying all the sides, because there are four sides. You only need to multiply two of them.
There is no formula for a rectangle. There are formula for calculating its area, perimeter or length of diagonals from its sides, or it is possible to calculate the length of one pair of sides given the other sides and the area or perimeter, or the two lots of sides given area and perimeter and so on.
You cannot have a trapezoid with three sides! Or if the question was something like 'You know three of the four sides of a trapezoid' ; that cannot be done either, because there is no way of calculating what the length of the fourth side is.
A trapezoid has two parallel sides, and two that are not. Call the distance between the two parallel sides the height (H). Add the length of the two parallel sides (L1 + L2), multiple this by the height (H) and then divide by 2. This can be experessed as - ((L1 + L2) * H ) / 2 Remember, L1 and L2 are the length of the parallel sides, and H is the distance between the parallel sides. We do not care about the length or angle of the other sides.
The recommended method for calculating the length of a shed roof rafter is to use the Pythagorean theorem, which states that the square of the hypotenuse (longest side of a right triangle) is equal to the sum of the squares of the other two sides. This formula can help determine the length of the rafter based on the roof's pitch and the span of the shed.
The area of a square (the word "rectangle" is redundant), with sides of length s units, is s^2 square units.
It depends on what information you have. In the simplest case, if you know the length of a sides of a square is x units, then the are is x*x = x2 square-units
Sides with the same length are congruent.
Tessellate2D shapesQuadrilateralfour sides
A Square has four equal length sides
no. one of the sides is a different length.
Scalene triangle has no sides of same length