The answer is 99 cm²
The area (A) of the triangle with base a and height h is:
A = a h / 2
A base is 3 cm greater than 5 times its height: a = 5h + 3
So, the function is:
A = a h / 2 = (5h +3) h / 2
If the height is 6 cm:
h = 6
A = (5h +3) h / 2
A = (5 6 + 3) 6 /2
A = 33 * 3
A = 99 cm²
