Question: What is the length of the altitude from vertex A(1, 1) to the base BC of triangle ABC with B(4, 1) and C(4, 5)?

Options:

1. 3
2. 4
3. 2
4. 5

Correct Answer: 3

Solution:

The base BC is vertical, so the length of the altitude is the horizontal distance from A to line x = 4, which is |4 - 1| = 3.