Assertion (A): An isosceles right triangle has area 8 cm². The length of its hypotenuse is 4 cm.

Reason (R): Area of an isosceles triangle with sides a, a and b is given by $\dfrac{1}{4}b\sqrt{4a^2 + b^2}$.

1. A is true, R is false

2. A is false, R is true

3. Both A and R are true

4. Both A and R are false

Assertion (A): The area of rhombus is 84 cm². If its one diagonal is 7 cm, then side of the rhombus is 12 cm.

Reason (R): Area of rhombus is given by $\dfrac{1}{2}$ × product of its diagonals.

1. A is true, R is false

2. A is false, R is true

3. Both A and R are true

4. Both A and R are false

A field is in the shape of parallelogram, whose adjacent sides are 120 m and 170 m. If its one diagonal is 250 m, then cost of ploughing the field at ₹20 per sq m is :

1. ₹ 90,000

2. ₹ 1,20,000

3. ₹ 1,80,000

4. ₹ 3,60,000

The base of an isosceles triangle is 16 cm and its area is 48 cm². The perimeter of the triangle is :

1. 24 cm

2. 30 cm

3. 36 cm

4. 42 cm