Before computers how did mapmakers create map projections a)with historical records b)with mathmatical formulas c)with economic forcasts d)with observation of natural distortions on earths surface

b) with mathmatical formulas

Explanation:

    Cartography was one of the areas of knowledge that was most impacted by scientific and technological development, especially in relation to electronics and computing. We can say that until the 60's of the last century, Cartography and its processes were classic. The development and improvement of equipment that would allow electronic distance measurement initiates this interaction, and then the first applications in electronic computers, which, even rudimentary - compared to what we have today -, allowed the first graphical visualizations of information, as well as its applications in database systems. It can be said, then, that electronics and computing were the greatest technological advances that brought new paradigms to Cartography.

i'm sure the answer you are looking for would be

a. an ice age

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