Respuesta :

A= a+b/2 *h

6.5 = a+4/2 * 2

6.5/2 = a+4/2 *2/2

3.25 = a+4/2

3.25*2= a+4/2*2
6.5 = a+4
6.5-4 = a+4-4
2.5 = a

The missing measure is 2.5

Check
6.5= 2.5+4/2 *2
6.5= 2.5+2*2
6.5=2.5 + 4
6.5=6.5