Error two rectangles intersection same location and size in c#

hi 

 

If two rectangles having same width and height and same location means do intersection and fill color. in my application i am skkipping this bcz if i not doing this means only intesected portion is not going to fill color, its Full rectangle is filling color so thatsy i skiiped but i need if two rectangles have same width and height and same location fill color and intrsected portion also need to color. how to do anybody help me. i did everything but this is the only error i am finding

 

thanks