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.
 
rectangle (1).png
 
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.
 
parallel and equal (1).png
 
\(AB = DC\) & \(BC = DA\)
Hence, Opposite side are equal and parallel
The Second property of the rectangle: All the angles of a rectangle are \(90°\).
 
angle.png
 
Let us consider a rectangle \(ABCD\).
\(∠A = ∠B = ∠C = ∠D\)
Hence, each angle of a rectangle measures \(90°\).
The third property of rectangle: Diagonals of a rectangle bisect each other.
 
diagonals.png
In rectangle \(ABCD\), diagonals bisect the angles.
\(OA = OC\) and \(OB = OD\)
Thus the diagonals bisect each other in a rectangle.