Answer:
10 cm
Step-by-step explanation:
[tex]A= \frac{1}{2} (a + b)h\\\\A= \frac{1}{2} (\frac{3}{2} +\frac{7}{2} )4\\\\A= \frac{1}{2}(\frac{10}{2})4\\\\A= \frac{1}{2}(5)4\\\\A= \frac{5}{2} *4\\\\A= 20/2=10[/tex]
