The graph below represents a section of the curve y = x(x−2)

From the given information, C is $(6, 0)$ and D is $(8, 0)$.

The slope $m$ is given by the formula $m = \frac{y_2 - y_1}{x_2 - x_1}$.

Since the slope is 0, the line is horizontal. The equation of a horizontal line is $y = k$, where $k$ is the y-coordinate of any point on the line. Both C and D have a y-coordinate of 0.
The equation of the line CD is $\boxed{y = 0}$.

1.ii) Distance AB

From the given information, A is $(0, 7)$ and B is $(0, 2)$.

The distance $d$ between two points $(x_1, y_1)$ and $(x_2, y_2)$ is given by the formula $d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.

The distance AB is $\boxed{5 \text{ units}}$.

2. Calculate the value of k

The points are $(6, k)$ and $(k, 10)$. The gradient $m$ is 2.

The gradient formula is $m = \frac{y_2 - y_1}{x_2 - x_1}$.

Multiply both sides by $(k - 6)$:

Add $k$ to both sides:

Add 12 to both sides:

Divide by 3:

The value of $k$ is $\boxed{\frac{22}{3}}$.

3.
The image provides a sketch of the curve $y = x(x-2)$ but does not state a specific question to be solved for this part. Therefore, I cannot provide a solution for question 3.