Acircle graph has three regions. one region is 2/5, the second is 9/20, what is the fraction of the third regions?

Can you draw an isosceles triangle with only one 80 degree angle?

If you answer right ill give brainliest, : )

Of the ones listed here, the factor that had the greatest impact on the eventual destruction of native americans' ways of life was the development of the a) automobile. b) highway. c) railroad. d) steamboat.