Area of a triangle = 1/2 * b * h
b = base
h = height
We know:
h = x
b = 4x
Area = 338ft^2
Let's plug these numbers into the Area formula above.
338ft^2 = 1/2 * 4x * x
First, let's divide both sides by 1/2
676ft^2 = 4x * x
Let's simplify the right side.
676ft^2 = 4x^2
Take the sqrt of both sides.
26 = 2x
Divide each side by 2
13 = x
Remember, the height = x = 13 feet