Affine transformations just scale the probability density by a constant, so a uniform distribution is still uniform.

ah, excellent point. thanks. this works if they are transforming the triangle to be a right triangle to make a rectangle but if they are making it half a square, that could not be accomplished solely with affine transformations (if I figure correctly...)

	▲	cluckindan 18 hours ago \| parent [-]
		But you can just map one right triangle to the other without affecting the distribution.