Which is the smallest blood vessel in the body?

What is the megasporangium also known as?

In any $\triangle ABC$,$r_1 r_2 + r_2 r_3 + r_3 r_1$ is equal to

The major product of the following reaction is

The incentre of the triangle formed by the lines $x+y=1$,$x=1$,and $y=1$ is

If $f: \mathbb{R} \rightarrow \mathbb{R}$ is such that $f(x+y) = f(x) + f(y)$ for all $x, y \in \mathbb{R}$,$f(1) = 7$,and $\sum_{r=1}^n f(r) = 14112$,then $n = $