Answer:
4 m
Step-by-step explanation:
We know that a triangle has half the area of a rectangle of the same height and width. That is, the rectangle that is as high and wide as the sail will have an area of 8 m². Of course, the area of a rectangle is the product of its length and width.
We know that 2×4 = 8 and that 4 is twice as much as 2. Thus the 4 dimension corresponds to the height of the sail, and the 2 dimension corresponds to its width.
The sail is 4 m high.