Since the formula is [tex] \frac{1}{2}h(B1+B2) [/tex], here's the answer.
First we do [tex] \frac{1}{2}10 [/tex], which gives us 5.
Then we do [tex]5(20+8)[/tex], which gives us [tex]5(28)[/tex].
At last we do [tex]5*28[/tex], and we get 140.
So, the answer would be 140.
Hope this helped! c:
