### Теория:

**Introduction:**

A parallelogram is a special kind of quadrilateral in which both pairs of opposite sides are parallel.

**The four basic properties of a parallelogram are:**

- Opposite sides of a parallelogram are equal
- Opposite angles of a parallelogram are equal
- Diagonals divide the parallelogram into two congruent triangles
- Diagonals bisect each other

There are three special types of a parallelogram, they are:

- Rectangle
- Rhombus
- Square

The following figure explains the special types of a parallelogram.

Important things to know about parallelogram

**Area of a parallelogram**

The area is the base times the height.

area\(= b × h\)

(\(h\) is at right angles to \(b\))

**The Perimeter of a parallelogram**

The perimeter is the distance around the edges.

The perimeter is \(2\) times the (base + side length):

Perimeter\(= 2(b+l)\)

**Diagonals of a parallelogram**

The diagonals of a parallelogram bisect each other.

In other words, the diagonals intersect each other at the half-way point.

In the next chapter, we will explore the properties of a parallelogram.

**Interesting fact:**

A parallelogram where all angles are right angles is a rectangle!