### Теория:

A rectangle is a quadrilateral with four right angles. In a rectangle, all the angles are equal \((360°/4 = 90°)\). Furthermore, the opposite sides are parallel and equal, and diagonals bisect each other.

Properties of rectangles:

- Opposite sides of a rectangle are equal and parallel.
- All the angles of a rectangle are \(90°\).
- Diagonals of a rectangle bisect each other.

**First Property of a rectangle:**Opposite sides of a rectangle are equal and parallel.

\(AB = DC\) & \(BC = DA\)

Hence, Opposite side are equal and parallel

**The Second property of the rectangle:**All the angles of a rectangle are \(90°\).

Let us consider a rectangle \(ABCD\).

\(∠A = ∠B = ∠C = ∠D\)

Hence, each angle of a rectangle measures \(90°\).

Hence, each angle of a rectangle measures \(90°\).

**The third property of rectangle:**Diagonals of a rectangle bisect each other.

In rectangle \(ABCD\), diagonals bisect the angles.

\(OA = OC\) and \(OB = OD\)

Thus the diagonals bisect each other in a rectangle.

Thus the diagonals bisect each other in a rectangle.