The lengths of the sides of some triangles in some unit are given below. Which of them is a right-angled triangle?

1. 7, 9, 13

2. 10, 24, 26

3. 6, 8, 12

4. 8, 12, 16

In △ABC, ∠B is a right angle. If D is the foot of the perpendicular drawn from B on AC, then:

1. BC² + CD² = AC²

2. AB² - BC² = AD² - CD²

3. BC² - BD² = AB² - AD²

4. None of these.

In the adjoining figure, AC =

1. 17 cm

2. 20 cm

3. 22 cm

4. 24 cm

The lengths of the diagonals of a rhombus are 5 cm and 12 cm. The length of each side of the rhombus is:

1. 13 cm

2. 6.5 cm

3. 6.25 cm

4. 5.25 cm