PC Optimization 1

You have 2 positive integers 'a' and 'b'. The product of a and b is 36. Find the 2 numbers with the smallest possible sum who still have a product of 36. In the applet below, you can use the slider to change 'a' which will in turn change 'b' so the product (area) is still 36. The line segment shows the sum of 'a' and 'b'.