Understanding Quadrilaterals - Revision Notes
CBSE Class 8 Mathematics
Revision Notes
Chapter – 3
Understanding Quadrilaterals
Revision Notes
Chapter – 3
Understanding Quadrilaterals
- Parallelogram: A quadrilateral with each pair of opposite sides parallel.
(1) Opposite sides are equal.
(2) Opposite angles are equal.
(3) Diagonals bisect one another. - Rhombus: A parallelogram with sides of equal length.
(1) All the properties of a parallelogram.
(2) Diagonals are perpendicular to each other. - Rectangle: A parallelogram with a right angle.
(1) All the properties of a parallelogram.
(2) Each of the angles is a right angle.
(3) Diagonals are equal. - Square: A rectangle with sides of equal length.
(1) All the properties of a parallelogram, rhombus and a rectangle. - Kite: A quadrilateral with exactly two pairs of equal consecutive sides
(1) The diagonals are perpendicular to one another
(2) One of the diagonals bisects the other.
(3) In the figure but . - Trapezium: A quadrilateral having exactly one pair of parallel sides.
- Diagonal: A simple closed curve made up of only line segments. A line segment connecting two non-consecutive vertices of a polygon is called diagonal.
- Convex : The measure of each angle is less than .
- Concave: The measure of at least one angle is more than
- Quadrilateral: Polygon having four sides.
- Element of quadrilateral:
(i) Sides: Line segments joining the points.
(ii) Vertices: Point of intersection of two consecutive sides.
(iii) Opposite sides: Two sides of a quadrilateral having no common end point.
(iv) Opposite Angles: Two angles of a quadrilateral not having a common arm.
(v) Diagonals: Line segment obtained by joining the opposite vertices.
(vi) Adjacent Angles: Two angles of a quadrilateral having a common arm.
(vii) Adjacent Sides: Two sides of a quadrilateral having a common end point.