Question 177395
The difference in bases is split between the two triangle bases (TB as shown in the diagram).
{{{44-20=24}}}
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{{{drawing( 300, 300, -5, 5, -5, 5,
line(-1,2,1,2),
line(-3,-2,3,-2),
line(-3,-2,-1,2),
line(3,-2,1,2),
line(-1,2,-1,-2),
line(1,2,1,-2),
locate(-2.7,0,L),
locate(-.75,0,A),
locate(-2.2,-2.2,TB)
)}}}
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So each triangle base (TB) is 12 units and the triangle altitude (A) is 16.
You can use Pythagorean theorem to solve for the trapezoid leg. 
{{{L=sqrt(12^2+16^2)=sqrt(144+256)=sqrt(400)=20}}}