9. unlike the portuguese, who had rounded africa and were sailing east toward asia, christopher columbus decided to sail his decision was based on his estimates of the circumference and the sizes of and unfortunately, columbus the former and the latter. although this resulted in a much longer voyage than he anticipated, his estimates probably convince and , the two spanish monarchs who sponsored his voyage. 

Unlike the Portuguese, who had rounded Africa and were sailing east toward Asia, Christopher Columbus decided to sail WEST. His decision was based on his estimates of the EARTH'S circumference and the sizes of ASIA and EUROPE. Unfortunately, Columbus UNDERESTIMATED the former and OVERESTIMATED the latter. Although this resulted in a much longer voyage than he anticipated, his estimates probably helped convince FERDINAND and ISABELLA, the two Spanish monarchs who sponsored his voyage.

West 
earths
asia
europe
underestimated
overestimated
ferinand
isabella