Answer:
Below
Explanation:
Area = 1/2 base * h and base + h = 20 ( then base = 20-h)
Area = 1/2 (20-h) *h
-1/2 h^2 + 10h <=== you could graph this to see the maximum or:
max occurs at (for a quadratic) h = -b/2a = -10/(2 *-1/2) = 10
then base = 20 -10 = 10 also
base = 10 height = 10