Regarding viewport question

Hi All:

I read that as per SVG 1.2 Tiny, only svg,image,video,animation element can
have their own viewport.  I saw that in SVG 1.1 there is something symbol
element which can have their own viewport, but symbol element is not
mentioned in SVG Tiny 1.2. So, my question is other than svg,
image,video,animation, is there any other element in SVG Tiny 1.2 which can
have their own viewport.

Let me explain the problem, so that you will understand it better.

Let's say i have a triangle which i have constructed using path
element.Thistriangle i want to draw at three places on my SVG canvas,
but each of the
triangle should be of different size.I can achieve it using transform
attribute, but my problem is i dont know the scale factor in advance.

what i want to do is that, on my canvas i can specify three rectangular
region each of different sizes, and when the triangle will be drawn in that
rectangular region, the triangle size will be changed automatically
depending on the rectangular region( let's assume i want to maintain aspect
ratio)

Can any one please help me.

Regs & Thanks.