Formulas and Tables

Elementary Geometry


Sides of a rectangle: \(a\), \(b\)
Diagonal of a rectangle: \(d\)
Radius of the circumscribed circle: \(R\)

Perimeter of a rectangle: \(P\)
Area of a rectangle: \(S\)

  1. A rectangle is a quadrilateral in which all four angles are right angles (equal to \(90^\circ\)).
  1. Diagonal of a rectangle
    \(d = \sqrt {{a^2} + {b^2}} \)
  2. Radius of the circumscribed circle
    \(R = d/2\)
  3. Perimeter of a rectangle
    \(P = 2\left( {a + b} \right)\)
  4. Area of a rectangle
    \(S = ab\)