
1. A quadrilateral is a polygon with four sides.
2. A quadrilateral with a pair of opposite sides are parallel is called a trapezium. If the nonparallel sides of a trapezium are equal it is called an isosceles trapezium.
3. If ABCD is an isosceles trapezium in which AB // CD and AD = BC, the diagonals are equal AC = BD.
4. If both the pairs of opposite sides of a quadrilateral are parallel, then it is called a parallelogram. 5. A quadrilateral is a parallelogram if its sides are equal, (or) its opposite sides are equal, (or) its opposite angles are equal, (or) its diagonals bisect each other, (or) if one pair of opposite sides are parallel and equal. 6. A parallelogram with one of its angles a right angle is rectangle. 7. A parallelogram whose adjacent sides are equal is rhombus 8. A rectangle whose adjacent sides are equal is a square. 9. A rhombus with one angle a right angle is a square. 10. A square is both rhombus and rectangle.
11. In a rhombus:
12. In a rectangle:
13. In a square:
Directions: Choose the correct answer. 