A) 1. EF/AB = SE/SA
EF = SE AB/SA = 27/12 = 9/4
SB² = SA² + AB² = 144 + 81 = 225
SB = 15cm
2. V = 1/3 * SA * AB² = 1/3 * 12 * 81 = 324 cm3
k = SE/SA = 3/12 = 1/4
V' = k^3 V = 324/64 = 5 cm3
B) 1. MN/AB = SM/SA
MN = SM AB/SA = 9x/12 = 3x/4 = 0.75x
2. A(x) = MN² = 0.5625x²
3.
0 2 4 6 8 10 12
0 2.25 9 20.25 36 56.25 81
