Concept in Definition ABC

Quadrilaterals are classified into three blocks: parallelograms, trapezoids, and trapezoids. The latter have a characteristic singular: lack parallel sides.

Characteristics of symmetrical trapezoids

They have two pairs of equal consecutive sides. Of these, the first pair of sides is different from the second, since one is less than the other. Its diagonals are perpendicular and therefore intersect at the midpoint of one of them. As the term indicates, they have an axis of symmetry. An example of this category It would be the deltoid (two joined isosceles triangles).

Characteristics of asymmetric trapezoids

They do not have equal consecutive sides, as one is larger than the other. On the other hand, its diagonals are different and oblique (not perpendicular). Likewise, they do not have axes of symmetry. It's the only kind of quadrilateral It does not have a defined shape, since it can have an infinite number of shapes. Consequently, to calculate its area it is normally divided into figures already known (for example, two triangles).

One of the bones of the hand

The trapezoid bone is part of the carpus and is found in the wrist along with three other bones: the trapezius, the great bone, and the hamate. All these small bones facilitate the mobility of the fingers of the hand.

This bone reminds us that other geometric figures serve to name different parts of the anatomy human, such as the deltoid, the trapezius or the pyramidal.

The different trapezoids

1) The trapezoid rectangle always has a 90 degree angle. One of its angles is acute (less than 90 degrees) and the other is obtuse (greater than 90 degrees). Consequently, there will always be a minor base and a major base.

2) The isosceles trapezoid has two equal sides that are not parallel and two other sides that are parallel. As for the angles, two are acute and two are obtuse. The diagonals are of the same measure and are therefore congruent. Finally, there is a minor and a major base.

3) The scalene trapezoid is one in which all its sides are different.

They all have one characteristic in common: they present a parallelism relationship between two of their sides, at least.

Parallelograms

There are three types of parallelograms: square, diamond and rectangle.

- The square has four sides and they are all the same. Its angles are 90 degrees. The two diagonals are equal and form a 90 degree right angle between them.

- The rhombus has all equal sides, but its angles are not right. Its diagonals are different, one major and one minor.

- The rectangle is similar to the square (of its four sides, two are short and the other two are long).

Photo Fotolia: Bunny

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