The figure (ii) given below shows the cross section of a concrete wall to be constructed. It is 2 m wide at the top, 3.5 m wide at the bottom and its height is 6 m and its length is 400 m. Calculate

(i) the cross sectional area and

(ii) volume of concrete in the wall.

The figure (iii) given below show the cross-section of a swimming pool 10 m broad, 2 m deep at one end and 3 m deep at the other end. Calculate the volume of water it will hold when full, given that its length is 40 m.

Area of a triangle is 30 cm². If its base is 10 cm, then its height is

1. 5 cm

2. 6 cm

3. 7 cm

4. 8 cm

If the perimeter of a square is 80 cm, then its area is

1. 800 cm²

2. 600 cm²

3. 400 cm²

4. 200 cm²