The midpoint theorem of a triangle states that the line segment in a triangle joining the midpoint of two sides of the triangle is said to be parallel to the third side and it is equal to half the length of the third side. Looking at the given triangle,
EF is the midsegment.
EF is the third side.
This means that
EF = 1/2TV
From the diagram,
EF = 7
Thus,
7 = 1/2TV
By cross multiplying,
TV = 7 x 2
TV = 14