If the lengths of diagonals of a rhombus is doubled, then area of rhombus will be

1. doubled

2. tripled

3. four times

4. remains same

If the length of a diagonal of a quadrilateral is 10 cm and lengths of the perpendiculars on it from opposite vertices are 4 cm and 6 cm, then area of quadrilateral is

1. 100 cm²

2. 200 cm²

3. 50 cm²

4. None of these.

In the adjoining figure, OACB is a quadrant of a circle of radius 7 cm. The perimeter of the quadrant is

1. 11 cm

2. 18 cm

3. 25 cm

4. 36 cm

In the adjoining figure, OABC is a square of side 7 cm. OAC is a quadrant of a circle with O as center. The area of the shaded region is

1. 10.5 cm²

2. 38.5 cm²

3. 49 cm²

4. 11.5 cm²