Answer:
Height is 12 meters
Explanation:
The area of a triangle is given by the formula:

Where
A is Area
b is base length
h is height
We are given "height is 6 MORE THAN twice the base", we can write this as:
h = 2b + 6
And, since it is given area is 18, we can put this into formula as:

Now we put the equation of height [ h = 2b + 6 ] into this and solve for b first:

Length can't be negative, so base = 3
We know h = 2b + 6, thus
h = 2(3) + 6 = 12
height is 12