A Fadama land surveyed to be triangular in shape has AB 1,000m and BC 2,000m was proposed for establishing banana plantation in the spacing of 400cm x 400cm. How many suckers will be needed to plant the Fadama land?

Assuming the given sides AB and BC are perpendicular (forming a right-angled triangle), the area of the triangular land is:

$$\text{Area of land} = \frac{1}{2} \times \text{base} \times \text{height}$$ $$\text{Area of land} = \frac{1}{2} \times 1,000\text{m} \times 2,000\text{m}$$ $$\text{Area of land} = \frac{1}{2} \times 2,000,000\text{m}^2$$ $$\text{Area of land} = 1,000,000\text{m}^2$$

The spacing is given as $400\text{cm} \times 400\text{cm}$.
Since $1\text{m} = 100\text{cm}$:

$$400\text{cm} = \frac{400}{100}\text{m} = 4\text{m}$$

So, the spacing is $4\text{m} \times 4\text{m}$.

$$\text{Area per sucker} = 4\text{m} \times 4\text{m}$$ $$\text{Area per sucker} = 16\text{m}^2$$

$$\text{Number of suckers} = \frac{\text{Area of land}}{\text{Area per sucker}}$$ $$\text{Number of suckers} = \frac{1,000,000\text{m}^2}{16\text{m}^2}$$ $$\text{Number of suckers} = 62,500$$

The number of suckers needed is $\text{62,500}$.