Hi, Idgagirls! :)
We can figure out how tall the sail is with the formula to the find the area of a triangle, which is:



Lets insert the information we already know:

Solve for h.
Divide both sides by 2.5.

Simplify.

Multiply both sides by 2.

h=3
The sail is 3 meters high.
Hope this helps.
-Benjamin