An ultralight plane si headed N30W at 40km/h. A 12km/h wind is blowing in the direction E20S. What is the resultant velocity of the ultralight plane with respect to the ground?
I cannot figure out how to draw the wind blowing E20S.
"In mathematics, you don't understand things. You just get used to them." -- Johann von Neumann
I would have wanted to solve the triangle using the cosine/sine law but I can not see an angle. If I go with a scale and 1cm=4km/h I get the resultant 7cm/21km/h
Any suggetions to solve it using trigonometry?
And you can still use geometry:
Put another direction at the upper tip of the triangle. From parallel lines, you know that the lower angle is 30 degrees. And since those angles are found in a right angle, you can deduce that the middle angle is 90 - (30 + 20) = 40 degrees.
From there, you can use the cosine rule and the sine rule to get angle x, which you use to determine the resultant angle.