What is the similarity ratio of the smaller to the larger similar pyramids? enter your answer as a: b.

The 'similarity ratio' is their fancy name for the ratio of
corresponding sides of two drawings that are 'similar'.

In these similar pyramids . . .

-- the 9 of the small one corresponds to the 12 of the big one.
Their ratio is  9/12 = 3:4 .

-- the 18 of the small one corresponds to the 24 of the big one.
Their ratio is  18/24 = 3:4 .

Notice that they're the same ratio.  If they WEREN't the same ratio,
then these two pyramids wouldn't be similar, even if somebody said
that they are. 

The similarity ratio for these two figures is  3:4 .

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