Answer:
x ≈ 6.6 cm
Explanation:
The Pythagorean theorem applies. The sum of the squares of the legs of this right triangle equals the square of the hypotenuse:
x^2 + 13.5^2 = (x+8.45)^2
x^2 +182.25 = x^2 +16.9x +71.4025
110.8475 = 16.9x . . . . . subtract x^2 +71.4025
6.559024 = x . . . . . . . .divide by 16.9
The value of x is about 6.6 cm.