Question 341277
You need to draw a triangle. One arm goes south, the other arm points east.


use the formula D=VT, where D=distance, V=velocity (speed) and T=time

Convert the times to hours with decimals (i.e. 2 hours and 30 minutes is the same thing as 2.5 hours)


South: D = (400)(2.5) = 1000 km
East: D = (420)(1.75) = 735 km


Now you should do Pythagorean theorem with 1000 as one arm, and 735 as the other arm.


Let the displacement = x


x^2 = 1000^2 + 735^2
x = 1241


So the plane is 1241 km away from where it started (as measured along the diagonal line).