9514 1404 393
Answer:
≈ 17.228101 cm
Step-by-step explanation:
The area of a trapezoid is given by the formula ...
A = (1/2)(b1 +b2)h
Filling in the given information, we have ...
99 = (1/2)((x+4) +(x-9))(x -4) = (1/2)(2x -5)(x -4)
198 = 2x^2 -13x +20
2(x -3.25)^2 = 199.125
x = 3.25 +√99.5625 ≈ 13.228101
Then the length of the larger base is ...
x+4 = 17.228101 . . . cm
