To find the coordinates of \( C \), we proceed with the slopes of sides and the equations of lines.
1. Slope of \( AD \):
\[ \text{Slope of } AD = 3 \]
2. Slope of \( BC \):
\[ \text{Slope of } BC = -\frac{1}{3} \]
Equation of \( BC \):
\[ 3y + x - 17 = 0 \]
3. Slope of \( BE \):
\[ \text{Slope of } BE = 1 \]
4. Slope of \( AC \):
\[ \text{Slope of } AC = -1 \]
Equation of \( AC \):
\[ x + y - 3 = 0 \]
Solving these equations, we find:
\[ \text{Point } C \text{ is } (-4, 7) \]
Since \( C \) lies on the circle, we have:
\[ x^2 + y^2 - 65 = 0 \]
The value \( 9 \int_{0}^{9} \left\lfloor \frac{10x}{x+1} \right\rfloor \, dx \), where \( \left\lfloor t \right\rfloor \) denotes the greatest integer less than or equal to \( t \), is ________.