(14 + 6) + 11 is equal to 14 + (6 + 11). The associative property of addition was used, which is when the equation is the same no matter how it is grouped.
(14 + 6) = 20, and 20 + 11 = 31.
(6 + 11) = 17, and 14 + 17 = 31.
They were grouped differently, but they had the same sum.
Notice how each measure of the segments for the red quadrilateral is 2x the amount of the segments for the blue triangle? That right there is the dilation factor.
