Final answer:
The y-intercept of line AB is 0, and the equation of line CD is y = 5.
Step-by-step explanation:
The y-intercept of a line is the point where it intersects the y-axis. In this case, we are given the coordinates of point A as (8, 0). Since the y-coordinate of point A is 0, the y-intercept of line AB is 0.
The equation of a line can be determined using the slope-intercept form, which is y = mx + b, where m represents the slope and b represents the y-intercept. The slope of line CD can be found by finding the difference in y-coordinates divided by the difference in x-coordinates between points C and D. In this case, the slope is (5 - 5) / (5 - 5) = 0. Therefore, the equation of line CD is y = 0x + b, where b is the y-intercept. Since point D has coordinates (5, 5), the y-intercept is 5. Therefore, the equation of line CD is y = 0x + 5, or simply y = 5.