For squares, I think the answer is the only real positive root of the equation 1 + r = r2 + r4 + r5 + r7 , or r = .830+. (The number in each square is the exponent of the side of the square.)
For triangles, in 2011, Maurizio Morandi improved my best packing. His best r is the positive root of the equation 1 + r = r2 + r3 + r5 + r9 , or r = .828+.
For hexagons, I think the answer is r = .807+.
Another interesting variant is to pack 1 polygon of side r1, 2 polygons of side r2, 3 polygons of side r3, and so on. In this case, the largest r value for both the square and triangle is φ=(√(5)-1)/2, and there is no wasted space at all!
