Respuesta :

Answer:

JN = 18.6

Step-by-step explanation:

Theorem:  The length of the midsegment of a trapezoid is the average of the bases.

[tex]JN = \frac{15.4 + 21.8}{2}[/tex]

       [tex]= \frac{37.2}{2}[/tex]

       = 18.6

See how easy that is when you know the theorem.