In the given figure, AB = BD, BC = 20 cm and ∠D = 45°, the length of AC is :

1. 54.64 cm

2. 48.28 cm

3. 40 cm

4. 14.64 cm

The measure of x correct to the nearest metre is :

1. 70 m

2. 35 m

3. 61 m

4. 140 m

The angle of elevation of the top of a tower from a point on the ground and at a distance of 160 m from its foot, is found to be 60°. Find the height of the tower.