Midsegment = 1/2(base1 + base2)
EF = 1/2(AB + CD)
EF = 1/2(20 + 12)
EF = 1/2(32)
EF = 16
Answer
EF = 16
First make the denominators the same = 4 5/20 - 3 12/20. Then make them improper fractions= 85/20-72/20= 13/20. Since that is already simplified the answer is 13/20.