the height is 10 feet more then its base and area equals 1200 feet?
H = b + 10
A = 1200 = bh
1200 = b(b + 10)
1200 = b^2 + 10b
b ^2 + 10b - 1200 = 0
- B +/- sqrt( B^2 - 4AC) - 10 +/- SQRT(10^2 -4(-1200))
b = --------------------------- = -------------------------------------------
2A 2
- 10+/- sqrt(4900)
b = -------------------------- = {- 10 + 70)/2 = 30
2
b = 30
h = 30 + 10 = 40
A = hb = 30*40 = 1200 feet^2