Step-by-step explanation:
Since PT = 2PM and AR = 2AD,
The midsegment MD must be the average of PA and TR:
Therefore we have
2(20x + 4) = 10 + (34x + 16)
=> 40x + 8 = 34x + 26
=> 6x = 18
=> x = 3
Hence length of MD
= 40(3) + 8 = 128.
