Please help this is earthy systems

What was one effect of european influence on southeast asia? new roads and railroads were constructed. rulers built palaces in the european architectural style. the vietnamese absorbed much of the european culture. the islamic religion spread throughout the region.

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

How would you find the measure of one interior angle