Loading...

Lesson: Geometry - 22

Rectangles

[Page 25 of 30]

The rectangle, like the square, is one of the most commonly known quadrilaterals. It is defined as having all four interior angles 90° (right angles). The diagonals of a rectangle are congruent.

A rectangle is a parallelogram with:

  • four right angles
  • equal diagonals that bisect each other

If a quadrilateral has one of these two features, it will have the other one, and is a rectangle. Rectangles have equal opposite sides.

The perimeter of a rectangle is the sum of the sides. Since there are two equal lengths and two equal widths, the perimeter of a rectangle is 2l + 2w.

Interior angles of a quadrilateral must sum to 360°, so we know that ∠ S = 360° - 3(90°) = 90°. This means that the opposite sides of QRST are of equal length, so QR=TS, QT=RS, and QS=RT.

Next to display next topic in the chapter.

Test Prep Lessons With Video Lessons and Explained MCQ

Large number of solved practice MCQ with explanations. Video Lessons and 10 Fully explained Grand/Full Tests.

More for You