Answer:
37 ft
Step-by-step explanation:
The ladder forms a right triangle as it elan's against the wall of the boat house.
Thus, the length of the ladder can be determined using Pythagorean theorem.
c² = a² + b²
c = length of ladder
a = 35 ft
b = 12 ft
Plug in the values
c² = 35² + 12²
c² = 1,225 + 144
c² = 1,369
c = √1,369
c = 37
Therefore, to reach the roof of the boathouse, the length of the ladder = 37 ft
310 - 220 = 90
90/310 = x/100 (cross multiplication)
9000 = 310x
9000/310 = x
x = around 29%
Assuming R and H:
So volume is pir^2 * H = 1500 and H = 1500/(pir^2) while surface area is A= 2pir*H + 2pir^2
A = 2pir(r+h)= 2piR^2 + 2pir*1500/(pir^2)= 2piR^2 + 3000/r
For A to take minimum, get the derivative 4pir - 3000/R^2 and let it be 0
4pir^3 - 3000 = 0
r = cbrt(3000/(4pi)) ≈ 6.20
h = 1500/(pi(6.20)^2) ≈ 12.42
