Given triangle ABC with vertices A(-6, -2), B(2,8), and C(6, -2). Line AB has midpoint D, line BC has midpoint E, and line AC has midpoint F.

Question

Given triangle ABC with vertices A(-6, -2), B(2,8), and C(6, -2). Line AB has midpoint D, line BC has midpoint E, and line AC has midpoint F. 
Which of the following statements is true?
1. ADEF is only a parallelogram
2. ADEF is a rhombus
3. ADEF is a rectable but not a parallelogram
4. ADEF is not a parallelogram

Steve · Answer

(1) because while AD || EF, AD=6 and AF = √41