What I am trying to do is take a square imageview and make it a 5 point imageview in the shape of a 3 point triangle at the top and the bottom to points in a base.
I want to take the top and make it bigger and keep the bottom half the same size. I do not want to mask or cut of some portion of the original image. I want to physical make the image bigger by stretching and not masking. I have not seen anything on this site that explains how to do this or if its possible.
Are you trying to modify the raster image or the vector?
When you are trying to change the rectangle to a triangle, is that interactive or is that based on some logic? If it is based on user interaction, then you need to convert the points into a vector and draw lines between them, and as these points are manipulated, your shape will too (like in any vector drawing application like Illustrator, Inkscape, etc)
Additional details will be helpful,