- A8
- B7
- C16
- D9
Step-by-Step Solution
Opposite sides of a parallelogram are equal. CD is opposite to AB, so CD = AB = 8 cm.
Answer: A) 8
In parallelogram ABCD, side AB = 8 cm. What is the length of side CD?
Class 8Understanding QuadrilateralsQuadrilaterals
Key idea: The quadrilateral family tree
Order from most general to most special:
```
Quadrilateral
├── Trapezium (one pair of parallel sides)
├── Kite (two pairs of adjacent equal sides)
└── Parallelogram (two pairs of parallel sides)
├── Rectangle (4 right angles)
│ └── Square (4 right angles + all sides equal)
└── Rhombus (4 equal sides)
└── Square (also)
```
A square is BOTH a rectangle and a rhombus — it's the most special kind of parallelogram. A rectangle and a rhombus are both parallelograms. Trapeziums and kites are quadrilaterals but not parallelograms.
```
Quadrilateral
├── Trapezium (one pair of parallel sides)
├── Kite (two pairs of adjacent equal sides)
└── Parallelogram (two pairs of parallel sides)
├── Rectangle (4 right angles)
│ └── Square (4 right angles + all sides equal)
└── Rhombus (4 equal sides)
└── Square (also)
```
A square is BOTH a rectangle and a rhombus — it's the most special kind of parallelogram. A rectangle and a rhombus are both parallelograms. Trapeziums and kites are quadrilaterals but not parallelograms.
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