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SAI International School
CLASS - VIII

Mathematics
CHAPTER-3: Understanding Quadrilaterals Lesson Notes-5

SUBTOPICS:SOME SPECIAL PARALLELOGRAMS

Rhombus: A rhombus is a quadrilateral with sides of equal length. Since the opposite
sides of a rhombus have the same length, it is also a parallelogram. So, a rhombus has
all the properties of a parallelogram and also that of a kite.

Properties of Rhombus:

 All the properties of a parallelogram.
 All sides are of equal length.
 Diagonals are perpendicular to each other.

Example: RICE is a rhombus. Find x, y, z.

Solution: x = OE = OI (diagonals bisect) = 5cm

y = OR= OC (diagonals bisect)= 12cm

z = side of the rhombus = 13 (all sides are equal)

Rectangle: A rectangle is a parallelogram with equal angles.

Properties of Rectangle:

 All the properties of a parallelogram.
 Each of the angles is a right angle.
 The diagonals, besides being equal in length bisect each other.
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