Question

Three of the vertices of a trapezoid are A(3,-3), B(12, 6) and C(4,8). The fourth vertex is labeled D. One of its bases is AB

What is the equation of the line that includes base CD?

Answer 1

y = x + 4

I graphed all the points, and the line that goes through AB is y = x - 6. The bases of a trapezoid are parallel, so the slope on the line CD has to be the same. I graphed the point C and just tried different y-intercepts to see which line would go through C.