You can
put this solution on YOUR website!Let x=height
Since the "base of a triangular sail is 5m shorter than its height", we have the equality

Start with the formula for the area of a triangle

Plug in

,

, and

Multiply both sides by 2

Distribute

Subtract 36 from both sides

Factor the right side (note: if you need help with factoring, check out this
solver)
Now set each factor equal to zero:

or

or

Now solve for x in each case
So our possible answers are

or
However, since a negative height doesn't make sense, our only solution is
So the height is 9 m
Now subtract 5 from the height to get the base
So the base is 4 m
Check:

Start with the formula for the area of a triangle

Plug in

,

, and

Multiply

Divide. Since the two sides of the equation are equal, this verifies our answer.