In the wind triangle, the line from C to A represents what?

• A. Wind direction and velocity
• B. Ground speed
• C. True course
• D. True airspeed

Answer: (A)

In the wind triangle, the line from C to A is the wind velocity vector. It encodes both how fast the wind is blowing (length of the line) and the direction it’s blowing toward (the line’s direction). This wind vector is the portion that, when combined with the aircraft’s speed through the air, produces the aircraft’s path over the ground—the ground-speed vector. The true airspeed is the velocity of the aircraft relative to the air (a separate vector along the heading), and the true course or ground track is the resulting path over the ground (another vector formed from the combination). So this line specifically represents the wind's direction and speed.