The area of the sector formed by joining the tips of \(\textbf{r}_2\) and \(\textbf{r}_3\) around the orbit is \(B_1\). The area of the sector formed by joining the tips of \(\textbf{r}_1\) and \(\tex...The area of the sector formed by joining the tips of \(\textbf{r}_2\) and \(\textbf{r}_3\) around the orbit is \(B_1\). The area of the sector formed by joining the tips of \(\textbf{r}_1\) and \(\textbf{r}_2\) around the orbit is \(B_3\). Our aim is to use this approximate Equation to find approximate values for the heliocentric distances at the instants of the three observations, and then to refine them in order to satisfy the exact Equation 13.2.5.
