Kinds of quadrilaterals

In your book, Maths Mela (Chapter 7, Shapes and Patterns), we fit the triangle pieces of the rhombus together to make 4-sided shapes, called quadrilaterals. One of them is a kite. Number its sides 1, 2, 3 and 4 going round. Side 1 is equal to side 2, and side 3 is equal to side 4. Side 1 and side 2 are next to each other; sides that are next to each other are called adjacent sides. So a kite has two pairs of equal adjacent sides.

The book shows two more quadrilaterals, A and B, that are not kites. In each of them, the sides that are across from each other, the opposite sides, are equal. Quadrilaterals whose opposite sides are equal are called parallelograms.

Now look at their angles. In parallelogram A, the opposite angles are equal, but they are not right angles: two opposite corners are pointed and the other two are wide. In parallelogram B, all four angles are equal, and they are all right angles. A parallelogram with all right angles is called a rectangle. So a rectangle is a special type of parallelogram.

To tell them apart, ask two questions. Which sides are equal: adjacent pairs (a kite) or opposite pairs (a parallelogram)? And are all the angles right angles (a rectangle)?