If $5 x-12 y+10=0$ and $12 y-5 x+16=0$ are two tangents to a circle, then the radius of the circle is

Given that, $5 x-12 y+10=0$ $\ldots$ (i) and $\quad-5 x+12 y+16=0$ $\ldots$ (ii) Slope of Eq. (i) $=\frac{5}{12}$ Slope of Eq. (ii) $=\frac{5}{12}$ Thus, Eqs. (i) and (ii) are parallel. Therefore, distance between parallel lines $=$ diameters of the circle. $\Rightarrow \frac{|10+16|}{\sqrt{25+144}}=2 \times$ Radius of the circle $\Rightarrow \quad 2 \times$ Radius of circle $=\frac{26}{13}$ $\therefore \quad$ Radius of circle $=1$