UNDERSTANDING QUADRILATERALS - ESSENTIAL POINTS
- Quadrilateral is a polygon having 4 sides.
- Parallelogram: A quadrilateral with pair of parallel opposite sides.
- Opposite sides are equal.
- Opposite angles are equal.
- Diagonals bisect one another.
- Rhombus: A parallelogram with sides of equal length.
- All the properties of a parallelogram.
- Diagonals are perpendicular to each other.
- Rectangle: A parallelogram with a right angle.
- All the properties of a parallelogram.
- Each of the angles is a right angle.
- Diagonals are equal.
- Square: A rectangle with sides of equal length.
- All the properties of a parallelogram, rhombus and a rectangle.
- Kite: A quadrilateral with exactly two pairs of equal consecutive sides
- The diagonals are perpendicular to one another.
- One of the diagonals bisects the other.
- One pair of opposite angles are equal.
- Trapezium: A quadrilateral having exactly one pair of parallel sides.
- Line segment connecting two non-consecutive vertices of a polygon is called diagonal.
- Convex: The measure of each angle is less than 180°.
- Concave: The measure of at least one angle is more than 180°.
- Elements of quadrilateral:
- Sides: Line segments joining the points.
- Vertices: Point of intersection of two consecutive sides.
- Opposite sides: Two sides of a quadrilateral having no common end point.
- Opposite Angles: Two angles of a quadrilateral not having a common arm.
- Diagonals: Line segment obtained by joining the opposite vertices.
- Adjacent Angles: Two angles of a quadrilateral having a common arm.
- Adjacent Sides: Two sides of a quadrilateral having a common end point
- Sum of external angles of a polygon is always 360°.
