If the straight sides of a triangular section of a lined canal with circular bottom of radius D, make an angle $$\theta $$ with horizontal, the hydraulic mean depth is
A. $${\text{D}}$$
B. $$\frac{{\text{D}}}{2}$$
C. $$\frac{{\text{D}}}{3}$$
D. $$\frac{{\text{D}}}{4}$$
E. $$\frac{{\text{D}}}{5}$$
Answer: Option B
How it will comes d/2