Reference: drawArrow
drawArrow(v) draws the arrow of the vector pointing from the origin to v ∈ R^2 in the current 2D visualization window. drawArrow(a, b) draws the arrow between the points a ∈ R^2 and b ∈ R^2. drawArrow(a, b, s) draws the arrow between the points a ∈ R^2 and b ∈ R^2 using the style (CSS) s. Example: drawArrow(❨0, 0❩, ❨3, 5❩, "line−colour:red; triangle−colour:red")