jmc

Let $x$ denote the measure of each of the two equal sides. Then the remaining side has measure $20-2x$ units. By the triangle inequality, the third side must be shorter than the two equal sides combined. In other words, $x+x>20-2x$. Solving this inequality, we find $x>5$. Also, the third side length has to be positive, so $20-2x>0$ which implies $x<10$. Therefore, the $\boxed{4}$ integers strictly between 5 and 10 are the possible integer values of $x$.