Question 819039
 <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
trapezoid with an area of 20 square inches,a height of 4 inches,
and a top length of 3 inches.   Find the base {{{green(x)}}}
 <img src='http://img809.imageshack.us/img809/1354/441b.png' border='0'/></a>
 {{{((3in + x)/2)4in = 20in^2}}}  ****
      6 + 2x = 20
          2x = 14
           x = 7", the length of the base
CHECKING our answer***
 {{{((3in + 7in)/2)4in = 20in^2}}}