congruency

And by this kind of congruency do we measure the bodies of all both liquid and dry things, to witt, by filling an equall place.

Here Euclide doth by congruency comprehende two peripheries in one, and so doe we comprehend them.

The Demonstration of this is from the rule of congruency: Because the whole agreeth to all his parts.

The matter is apparent by congruency or application: as here in this example.